Al-Qaeda leader Osama Bin Laden is alive and planning further high-profile terrorist attacks around the world, the head of Interpol has said.

Ronald Noble told the French newspaper Le Figaro: ''Osama Bin Laden is alive, and on the ground the hunt for him goes on as it did on the very first day.

This message is not at all reassuring - it suggests a kind of co-ordination of terror

Interpol head Ronald Noble

''As long as I have no proof to the contrary, I will consider Bin Laden a fugitive well and truly alive.''

Mr Noble, who became Interpol's secretary general two years ago, added: ''Intelligence experts all agree that right now al-Qaeda is preparing a high-profile terrorist operation, with attacks targeting not just the US but several countries at the same time.''

The BBC's security correspondent Frank Gardner says this is the strongest yet assessment of the risk of al-Qaeda attacks.

Problem spreading

Mr Noble said al-Qaeda appeared to be lying low and allowing other "middle-ranking" terrorist groups to carry out attacks, such as the bombing in Bali and the theatre siege in Moscow.

''The battlefield now spreads across every country and mobilises several terrorist groups,'' the American head of the Lyon-based police organisation said.

Noble puts Bin Laden's fortune at $300 million

''This message is not at all reassuring. It suggests a kind of co-ordination of terror.''

French Interior Minister Nicolas Sarkozy said on Friday that a number of people arrested this week in France had links with the al-Qaeda network.

The eight arrests in Lyon and one in Marseille were made in connection with the bombing of a synagogue in Tunisia in April, which killed 19 people.

Sleeper cells

Interpol has also concluded that Bin Laden's wealth is largely intact, despite attempts to block al-Qaeda's cash flows.

Mr Noble estimated Bin Laden's fortune at about $300m.

The money is kept mainly in cash and is spread among several countries.

The Bali bombing: done in the name of al-Qaeda?

''The terrorist threat... is at least as great now as it was before 11 September. Sleeper cells are in place, unknown to the police, who are ready to act from one day to the next," Mr Noble said.

This is the first time this year that a senior security official has said he thought the Islamist network was still capable of major simultaneous attacks.

In the interview, Mr Noble said the recent operations in Bali, Yemen and Moscow showed that terrorist groups were sending a message to Western governments: "Your war against terrorism is far from over.''

Western intelligence agencies say the volume of information about al-Qaeda's activities has been increasing throughout the summer.

Part of it comes from electronic eavesdropping, and part of it is a result of interrogation of high-level prisoners.

Dead or alive?

There has been no concrete evidence about the whereabouts of Bin Laden since the US-led attacks on Afghanistan's Taleban regime last year.

However, the Arab satellite TV channel al-Jazeera has played a series of messages in the past two months that it says are from the al-Qaeda leader.

In September it played a recording of what it said was Bin Laden's voice naming all 19 hijackers from the 11 September terrorist attacks on the United States.

Last month, the channel broadcast a two-minute recording, again said to be Bin Laden, which threatened a strike ''against US economic interests" if Washington did not halt attacks on Arab and Muslim countries.

Soon after al-Jazeera carried a message in which ''Bin Laden'' praised attacks on US Marines in Kuwait and on a French super tanker off Yemen.

However, several leading figures in the war on terrorism have suggested Bin Laden might be dead.

They include Pakistan's President Pervez Musharraf, Afghan President Hamid Karzai and FBI counter-terrorism chief, Dale Watson.