By ANDREW BUNCOMBE

WASHINGTON - Somewhere in the mountains of Tora Bora the hydra's head may have been cut off.

But 12 months after the attacks of September 11 it is clear that it does not really matter whether Osama bin Laden is alive or dead.

Investigators say his al Qaeda organisation, though disrupted, has not been wiped out and is preparing to launch more terror attacks. As with the mythical beast, the monster may now be even stronger.

The most visible sign of al Qaeda's continued capabilities came in April when 19 people, including 14 German tourists, were killed in a bombing at a Tunisian synagogue.

Two months later, al Qaeda claimed responsibility and spokesman Sulaiman Abu Ghaith claimed 98 per cent of the al Qaeda leadership, including bin Laden, was still alive.

Part of the problem is that the military operation in Afghanistan failed to kill or capture most al Qaeda leaders or members, now believed to be active in up to 60 countries.

The United States says it has either killed or seized 12 al Qaeda leaders in the past year. Of these, bin Laden's military commander, Mohammed Atef, killed by an air strike in November, and senior operational aides Abu Zubair al-Haili, and Abu Zubaydah, who are both in US custody, are the most senior.

But most remain at large, having fled Afghanistan. Some of the important havens are believed to be Yemen, the Pankisi Gorge in Georgia, northern Iraq and Iran, where two key al Qaeda leaders, Saif al-Adel and Mahfouz Ould al-Walid, aka Abu Hafs the Mauritanian, are in hiding.

But the most important area is along the Afghanistan-Pakistan border where several hundred fighters are based. Yesterday it was reported that al Qaeda is again regrouping inside Afghanistan.

Counter-terrorism officials say the most-wanted al Qaeda members are bin Laden's deputy Ayman al-Zawahri, financial chief Shaikh Saiid al-Sharif and operational planner Khalid Shaikh Mohammed, suspected of carrying out the attacks on the Tunisian synagogue. Mohammed and al Qaeda colleague Ramzi bin al-Shaibah were interviewed by al Jazeera in Pakistan for a programme broadcast this week.

Even in the US there are estimates that there could be hundreds of al Qaeda sympathisers or operatives.

"There are a lot of potential or maybe active al Qaeda agents in the US," said Senator Richard Shelby, vice-chairman of the Senate Select Committee on Intelligence, in July. "They don't have, I believe, at the moment the central command they did with Osama bin Laden, but they're well-trained and I think you have to recognise they're dangerous."

Despite efforts to freeze the finances of al Qaeda much of its wealth remains untouched.