US begins air strikes against Islamic State in Syria

Where do key countries stand on Islamic State? Bahrain, Saudi Arabia, the UAE, Qatar and Jordan have all signed a communique pledging to fight IS.

US media are reporting that Bahrain, Jordan, Qatar, Saudi Arabia and the UAE are the Arab countries involved in the strikes in Syria - citing anonymous US officials.

Earlier this month, US President Barack Obama said that any group that threatened America would "find no safe haven", including inside Syria.

A quick recap. The US says it has started air strikes in Syria against the Islamic State militant group, in collaboration with "partner nations". The BBC special report on Islamic State has more background on the ongoing crisis.

tells the BBC "an obvious target for a first round of air strikes" would be the IS headquarters in Raqqa. "This is a well-known, well-identified building that they've been using for well over a year and they're really operating in plain sight," he says.

PJ Crowley says the Syrian government is "probably delighted that the international community is dropping weapons on Islamic State".

The US will be keen to make clear that people understand the air strikes are attacks against IS, not attacks helping the Syrian regime, he adds.

PJ Crowley, former US assistant secretary of state, tells the BBC the air strikes are "a very significant action by the US and in particular by several Sunni majority countries. The neighbourhood is taking the lead in striking at what has been an ISIS [IS] safe haven in Syria."

This is only a first step. The Pentagon acknowledges that air power alone is not going to defeat Islamic State, and crucial to that goal will be equipping and training the free Syrian Army. What we can say is that the campaign against Islamic State has now begun in earnest.

"We have five Arab Muslim Sunni-based nations attacking a Sunni-based terrorist organisation and that is... something we have not seen in the past. That is really quite an accomplishment," Gen Jack Keane adds.

General Jack Keane, a former vice-chief of the US Army, tells the BBC the air strikes are "really quite significant".

There are reports of IS fighters in Raqqa City fanning out and heading towards the rural areas. Some reports suggest IS ordered the evacuation of its HQs in Raqqa following suspicions of a circling drone. (BBC Monitoring)

Social media posts suggest that there have been airstrikes in Raqqa City, BBC Monitoring reports. Buildings said to have been hit there include the Governor's House, The Equestrian Club and the National Hospital.

Josh Rogin, a senior correspondent at US news site Daily Beast, tells the BBC that the "contribution of the Arab nations is largely symbolic". The real firepower will be coming from the US, he says.

Syria presents a different situation for the Obama administration compared to Iraq - the Iraqi government invited the US, whereas the Syrians have not, so this puts the US in the position of bombing an Arab country without the country's consent.

The jihadist group Islamic State has seized large swathes of territory in eastern Syria and across northern and western Iraq. It is known for brutal tactics including mass killings. The BBC looks at what the group wants.

The UK Ministry of Defence tells the BBC the UK "has not committed anything yet. Conversations are ongoing... We have not ruled ourselves out."

Arab nations are involved in the air strikes. Which ones and in what capacity they are involved has not been spelled out but we understand this will be made clear in the coming hours.

The BBC has learned that Arab nations are among those involved in the air strikes in Syria, but there is not yet confirmation which states are involved.

More from Adm John Kirby: "Given that these operations are ongoing, we are not in a position to provide additional details at this time... We will provide more details later as operationally appropriate."

The announcement came in a statement from Pentagon Press Secretary Rear Admiral John Kirby: "I can confirm that US military and partner nation forces are undertaking military action against ISIL [Islamic State] terrorists in Syria using a mix of fighter, bomber and Tomahawk Land Attack Missiles."

After weeks of air strikes against IS in Iraq, this is the first time the US has launched operations inside Syria against Islamic State (IS) targets.

The Pentagon has announced that the US military "and partner nation forces" are undertaking military action in Syria.

Hello and welcome to the BBC's live coverage as news emerges that the US and other nations have begun air strikes inside Syria against the jihadist group Islamic State.