THE British embassy in Saudi Arabian capital Riyadh will close to the public today because of an "imminent" terrorist threat, the Foreign Office said.

The British consulate in Jeddah and trade office in al Khobar will also close.

It is expected the offices will reopen on Saturday, although the situation will be kept under review.

The closure follows a similar move by the US over fears that terrorist attacks are imminent in the country, following a series of explosions in Riyadh last week which killed 34 people.

Investigators believe about 50 hard-core Muslim militants were ready to volunteer for suicide strikes.

Meanwhile, tactics to combat suicide bombers who target Britain are being urgently reviewed in the wake of the atrocities in Riyadh and Casablanca, the UK's top anti-terrorist officer said.

Assistant Commissioner David Veness, head of Scotland Yard's anti-terrorist branch, said UK officers were continuing to liaise with countries which have experience of suicide bombers to improve measures at home.

In Turkey, police are investigating whether a woman terrorist was killed by a bomb that exploded prematurely in a cafe in the capital yesterday.

One person was also wounded in the blast at the Crocodile Caf, on one of Ankara's busiest junctions.

* Radical cleric Abu Qatada is the most significant extreme Islamist preacher in the UK and has been an inspiration for terrorists including the lead hijacker behind the September 11 attacks, the Government claimed yesterday.

Mr Qatada, who was arrested under Home Secretary David Blunkett's anti-terrorism laws in October, is expected to appeal against his detention without trial.

But ministers believe he has close links to Osama bin Laden's al Qaida network and has been directly involved in terrorist operations.

The claim was contained in evidence revealed yesterday in the appeal by three foreign terror suspects against their detention without charge or trial under the Anti-Terrorism, Crime and Security Act 2001.