London ? Britain announced cuts in its forces in Iraq on Monday by 10 percent and has begun handing over their duties to Iraqi security forces, despite spasms of violence in recent weeks that have pushed the country closer to civil war.

Defense Secretary John Reid told the House of Commons that the reduction of 800 soldiers was possible because Iraqi security forces are becoming more capable of handling security in Iraq’s southern Basra region.

“This is a significant reduction which is based largely on the ability of the Iraqis themselves to participate and defend themselves against terrorism,” Reid said. “But there is a long, long way to go.”

The move was announced despite growing doubts about the reliability of Iraqi security forces in the Basra area, especially the police, which British officials believe have been heavily infiltrated by Shiite militiamen.

Following the Feb. 22 blast at a Shiite shrine in central Iraq, Basra police failed to stop attacks on Sunni mosques or prevent gunmen from breaking into a prison, hauling out 12 inmates, and shooting them to death.

Reid said the increase in violence had no impact on the decision to pull troops from the region.

British troops also have suffered the fallout from video images that appeared to show soldiers dragging several Iraqis into a compound and beating them with their fists and batons after a street demonstration.

The images have soured relations between Iraqi officials and the 8,000 British troops based in Iraq. The video allegedly was shot in the flashpoint town of Amarah, 150 miles north of Basra.

Reid acknowledged there were problems.

“And I have been absolutely clear that we are not yet at the stage where whole provinces could be taken under the responsibility of Iraqi security forces,” he said. “We continue to assess that. When those conditions are met, I will make another announcement to this house.”

Britain had 46,000 military personnel in Iraq during combat operations in March and April 2003. That dropped to 18,000 in May 2004, and to 8,500 at the end of 2005.

At the time of the last withdrawal of British troops in October, Reid said there were 190,000 members of the Iraqi security forces trained and equipped. Now the total is 235,000, and 5,000 more join every month, he said.

In Washington, Scott McClellan, the White House spokesman, said the British decision was made in coordination with coalition forces.