BAGHDAD (Reuters):

British Prime Minister Tony Blair pledged yesterday to support Iraq's government as it battles instability underscored when gunmen carried out a mass kidnapping at a Red Crescent office in the capital.

Just before Blair landed in Baghdad for an unannounced visit, police said 10 to 20 people were seized from the Red Crescent's Baghdad office but the aid agency said more were snatched. Witnesses said the gunmen arrived in pickup trucks.

"They took all the men, separated them from the women and left," a witness told Reuters. Those snatched included Red Crescent employees, visitors and guards.

"We call for their immediate and unconditional release," said Antonella Notari, spokeswoman for the International Committee of the Red Cross (ICRC) in Geneva.

She said at least 25 people had been taken by gunmen from among staff and visitors. ICRC carries out much of its work in Iraq through the Red Crescent. No ICRC personnel were snatched.

The Iraqi Red Crescent, the only Iraqi aid agency working in Iraq's 18 provinces, has 1,000 staff and 200,000 volunteers.

Baghdad is plagued by daily kidnappings, many of which are carried out by armed groups on either side of the conflict between majority Shi'ites and minority Sunni Arabs.

Blair said he and Iraqi Prime Minister Nuri al-Maliki had discussed the need for national reconciliation and building up Iraq's security forces to fight soaring Shi'ite-Sunni sectarian violence that has pushed the country close to all-out civil war.

"We stand ready to support you in every way that we can so that in time the Iraq government and the Iraqi people can take full responsibility for their affairs," Blair, who is touring the Middle East, told a news conference.

Later, an Iraqi militant group linked to al-Qaida urged Iraq's Sunni Muslims in a Web recording posted yesterday to wage war on the country's Shi'ite Muslims.

"Stand like one man ... and cut their (Shi'ites') throats, spill their blood, burn the ground underneath them, and rain bombs on them," said the speaker, who said he was the official spokesman of "the Islamic state in Iraq".

Iraqi Sunni militant groups including al-Qaida announced in October the creation of what they described as an Islamic state in Iraq.

The visit by Blair, Washington's closest ally, comes as U.S. President George W. Bush is rethinking his Iraq strategy following the defeat of his Republicans in mid-term elections and in the face of mounting U.S. military casualties.

Blair, his legacy tarnished by Iraq, defended London's plans for a gradual withdrawal of its 7,200 troops in the south, mostly in and around oil-rich Basra.

Meanwhile, Senate Democratic Leader Harry Reid said yesterday he would support a short-term increase in U.S. troop numbers in Iraq being weighed by President George W. Bush if it is part of a broader withdrawal plan.

Bush has been talking with experts about a new Iraq strategy and a short-term increase in American troops to help make Baghdad more secure is one idea that has been presented to him.

"If it's for a surge, that is, for two or three months and it's part of a programme to get us out of there as indicated by this time next year, then, sure, I'll go along with it," Reid, who will become the majority leader when Democrats take control of the Senate next month, told ABC's This Week programme.