US Edition The suspension, which will come into force from midnight, is a "precautionary measure" based on "possible contact between al-Qaida in Yemen and terrorist groups in Somalia, as well as concern about airport security in Mogadishu", Mrs May told MPs.
Toner cartridges larger than 500g (17.6oz) will also be banned from hand baggage on flights departing from the UK and also on cargo flights unless they originate from a regular shipper with security arrangements approved by the Department for Transport, she said.
Mrs May told MPs: "We are in a constant battle with the terrorists. They are always looking for another way, another innovative way, in which they can try to get around our defences.
"Our job, and the job of our security and intelligence agencies and the police, is to ensure that we are doing all we can to make sure that there are no gaps in our defences."
Mrs May said there was no information to suggest that another similar attack was imminent, but authorities were working "on the assumption that this organisation will wish to continue to find ways of also attacking targets further afield".
Department for Transport officials were in technical discussions with the industry to discuss the next steps, she said.
Earlier, Prime Minister David Cameron told MPs Britain must take every possible step to "cut out the terrorist cancer" that exists in the Arabian Peninsula.
The Prime Minister warned the threat from the region, particularly Yemen, had increased and the world needed to "come together to deal with this".
He made the comments after chairing a crisis meeting of Cobra, the Government's emergency planning committee, which discussed the plot and what implications it could have on air transport security.
Both bombs found last week were transported in the hold of passenger flights, suggesting that the terrorists were targeting tourists and other travellers, rather than simply trying to bring down cargo planes, as had previously been thought.
German officials disclosed that the two bombs contained 300 grams and 400 grams of explosive PETN.
Before the address to MPs on the terrorist threat, Downing Street admitted that the Prime Minister was only informed of the discovery of an explosive device on a cargo plane at East Midlands Airport several hours after it was found, much later than US President Barack Obama.
Mr Cameron praised the authorities involved in foiling the plot, saying they "clearly prevented the terrorists from killing and maiming many innocent people".
But he urged the "Arab world to cut out the terrorist cancer that lurks in the Arabian Peninsula".
"Clearly the whole country has been focused this weekend on the terrorist threat," Mr Cameron told the Commons.
"I want to put on record my thanks, and the thanks of everyone in this House, for all those involved in the international police and intelligence operation, whose efforts clearly prevented the terrorists from killing and maiming many innocent people whether here or elsewhere in the world.
"The fact that the device was being carried from Yemen to the UAE, to Germany to Britain, en route to America shows the interest of the whole world in coming together to deal with this."
He added: "While we are rightly engaged in Afghanistan to deny the terrorists there, the threat from the Arabian Peninsula, and from Yemen in particular, has grown."
"So as well as the immediate steps which the Home Secretary will outline, it's clear that we must take every possible step to work with our partners in the Arab world to cut out the terrorist cancer that lurks in the Arabian Peninsula."
Home Secretary Theresa May, who will deliver a more detailed statement on the incident in the House of Commons later on Monday, told MPs the plot was a "stark reminder of the harm our enemies wish to inflict upon us".
The government could leave passengers facing a raft of safeguards as the Government undertakes a new review of security on passenger jets, it was claimed.
Industry figures fear it could lead to a new, and unnecessary, overhaul of airport security after investigators concluded that the terrorists had designed a package to blow up passenger jets in a Lockerbie-style terrorist outrage.
Ministers and officials were understood to have discussed tougher checks on freight.
The review could lead air passengers to be subjected to "ludicrous" new security measures, the boss of budget airline Ryanair.
Earlier Michael O'Leary, the airline's chief executive, said authorities might now make travel "even more uncomfortable and tedious" for travellers.
The device found at East Midlands airport on Friday had left Yemen on a passenger aircraft, The Daily Telegraph has learnt, before it was switched to a UPS cargo plane. The second device, found in Dubai, was carried on two Qatar Airways passenger flights before it was intercepted.
Sources close to the investigation in Yemen said because there were no scheduled cargo flights out of the country it was likely the terrorists knew the bombs would be loaded on to passenger planes for at least part of their journey.
A United Arab Emirates security source said authorities were tracing the serial numbers of a mobile phone circuit board and computer printer used in the devices.
The Emirates were sharing the bomb part serial numbers with the US, Yemen and other countries involved in the probe in an effort to track the bombs' origins, the source said.
Meanwhile, the FBI and Homeland Security Department in the US warned local officials across the country that packages from abroad with no return address and excessive postage required a second look.
German aviation agency spokeswoman Cornelia Cramer said passenger flights from Yemen were being suspended until further notice after the country stopped package deliveries from Yemen over the weekend.
Ms May has admitted it was possible that the US-bound bomb found at East Midlands could have detonated over Britain if it had not been found, because of the unpredictability of freight routes.
The two bombs, concealed inside computer printers, were virtually impossible to detect by X-ray screening because they contained an odourless explosive and used timers that would have looked like part of the printers’ electronics.
They were designed to explode in mid-air and would have been as capable of bringing down an aircraft as the device that blew up PanAm Flight 103 over Lockerbie in 1988, killing 270 people.
More than half of all freight to the US is carried on passenger flights and Lord Carlisle of Berriew, the former government adviser on terrorism, said there was every chance a parcel bomb could end up on a passenger plane.
“If you put a parcel into UPS, you have no way of knowing what flight it is going to go on,” he said. “It could end up on a passenger flight.”
One of the bombs went to Dubai via Doha in Qatar on a passenger aircraft. The device that was found at East Midlands airport left the Yemeni capital of Sana’a on a passenger aircraft, which is also thought to have stopped at Doha, before it travelled to Cologne in Germany and Britain in cargo planes.
After investigators in Yemen confirmed that they were examining 26 other packages, John Brennan, President Barack Obama’s counter-¬terrorism adviser, said “it would be very imprudent … to presume that there are no other [bombs]".
Mr Brennan described the bombs as “sophisticated”, adding: “They were self-contained. They were able to be detonated at a time of the terrorists’ choosing.”
He said the plot “bears the hallmark” of al-Qaeda in the Arabian Peninsula (AQAP), the terrorist organisation’s Yemeni-based operation, whose leaders include Anwar al-Awlaki, an American-born preacher.
The most likely bomb maker is said to be Ibrahim Hassan al-Asiri, who made the device used in the foiled Christmas airline attack over Detroit.
The bombs, which were addressed to two synagogues in Chicago, contained the contact details of a 22-year-old computing student, Hannan al-Samawi, who was arrested on Saturday night.
However, investigators released her at the weekend and said they were now seeking another woman who it was thought had posted the devices using Miss al-Samawi’s personal details.
Intelligence that foiled the plot may have come from Jabir Jubran al-Fayfi, a former leading member of AQAP, who surrendered to the Saudi authorities last month.
In light of the plot, the US National Transportation Safety Board is re-examining the wreckage of a UPS cargo jet that crashed in Dubai in September, although sources in Dubai said there was no evidence of an explosion.
American officials expressed concern at the fact that the bomb at East Midlands was discovered only during a second police search.
David Cameron said the Government would “take whatever steps are necessary” to keep British people safe, but Downing Street was forced on to the defensive after the Prime Minister took until 6pm on Saturday – 26 hours after he was first briefed on the incident – to make a public statement.
It was left to Mr Obama, and later Mrs May, to break the news that viable devices had been found. Sources said Mr Cameron “wanted ministers to take the lead”.
Balpa, the pilots’ union, said it had warned for years of the threat from cargo, suggesting that the focus on checking passengers and their luggage “left the door open” for attacks by other means.
Labour leader Ed Miliband, who was briefed by Mr Cameron on Saturday on the plot, also thanked the police and the security services. He pledged the "full support" of the Opposition "in your efforts to tackle terrorism and keep the nation safe"