Britain has postponed a plan to withdraw around 1,500 troops from Iraq after a surge in violence swept the southern city of Basra and other Shiite areas, Britain's defense secretary said Tuesday.

Defense Secretary Des Browne said military commanders are putting on hold a plan to reduce British troop numbers from 4,000 to 2,500, as outlined by Prime Minister Gordon Brown late last year.

Browne said it would be "prudent" to pause any further reductions while the situation was unfolding.

Britain has about 4,000 troops stationed at an air base on the fringe of Basra. Forces withdrew from the city center late last year and began to focus only on training Iraqi troops and police.

Violence erupted after Iraqi Prime Minister Nouri al-Maliki launched a crackdown against Shiite militias in Basra. Street battles left more than 200 dead, including civilians, Iraqi troops and militants, and forced British troops back into combat.

The British army joined in the fighting for the first time Saturday, firing artillery to support an operation by Iraqi soldiers, military officials said.

"At this stage we intend to keep our forces at their current levels of around 4,000 as we work with our coalition partners and with the Iraqis to assess future requirements," Browne said.

He gave no timetable to reduce British troop numbers in the future, but said he will update lawmakers later this month.

PHOTO CAPTION

British soldiers secure the site at the scene of a bomb attack east of Basra, 550 kms south of Baghdad, in 2007.

AP