"The risk of indiscriminate terrorist attacks in public places including tourist sites will be especially high during military action in Iraq," the Foreign Office said in a statement.

The statement urged British citizens to be vigilant, take sensible precautions, be aware of local sensibilities, monitor the media and check travel advice for the country they live in or planto visit.

The warning came as US President George W. Bush declared diplomacy closed before his 0100 GMT Thursday deadline for Iraqi President Saddam Hussein to go into exile or face war.

It thus replaced a more bland and nonspecific general warning about the need for vigilance while traveling.

The British Foreign Office had warned Britons should be very careful and avoid nonessential travel to south-eastern Turkey.

The region, which is heavily populated by Kurds and borders Iraq, is not one of the primary tourist destinations for the country.

UK nationals in Saudi Arabia, Syria and Qatar have also been warned by the Foreign Office that they face a "high" threat from terrorism, possibly chemical or biological.

(Xinhua News Agency March 20, 2003)