Baghdad: British Foreign Secretary David Miliband made an unannounced visit to Baghdad yesterday and held talks with Iraqi Prime Minister Nouri Al Maliki at which he was expected to back Maliki's crackdown on Shiite militias.

A British embassy spokeswoman gave no details about the talks, which followed a meeting of Iraq's neighbours and Western powers that both Miliband and Maliki attended in Kuwait on Tuesday. Maliki launched the operation against Shiite militias late last month in the southern city of Basra, triggering widespread clashes with the Mahdi Army of Shiite cleric Moqtada Al Sadr.

Britain has around 4,000 troops stationed at an airbase on the outskirts of Basra. It delayed pulling up to 1,500 soldiers out of Iraq in the wake of that unrest.

While fighting has eased in Basra, Iraq's hub for most of its oil exports, clashes have taken place every day in and around the cleric's eastern Baghdad stronghold of Sadr City.

In the latest violence, Lieutenant-Colonel Steven Stover, a US military spokesman, said troops were attacked on their way to raid a psychiatric hospital not far from Sadr City.

Roadside bombs

He said soldiers were attacked by roadside bombs and small arms fire, prompting the US military to call for helicopter support. Four gunmen were killed, Stover added. Iraqi forces eventually raided the Al Rashad psychiatric hospital but made no arrests, he said.

The hospital has been under the spotlight since its acting director was held on suspicion he was involved in passing on details of patients to Sunni Islamist Al Qaida.

He was released last week after being detained for two months. It was unclear if he was ever charged. Hundreds have died in Shiite areas of Baghdad since Maliki launched his crackdown on the Mahdi Army. Al Sadr has demanded a withdrawal of US troops from Iraq and threatened over the weekend to wage "open war" if Maliki did not call off the campaign against his fighters.

Since Al Sadr issued his threat of war - which could unravel months of security gains while US forces are drawing down -the US military says it has killed more than 70 fighters in Sadr City and other Shiite parts of Baghdad.