IMPEACH BUSH

Six more US soldiers have been killed in Iraq, the military announced on Thursday, confirming that May has become the deadliest month for American forces in two-and-a-half years.

The number two US commander in Iraq, Lieutenant General Raymond Odierno admitted to reporters Thursday that violence was on the rise in Iraq, particularly in Baghdad, despite recent increases in US troop levels.

"We've made small progress here. We have not made the progress that I think is necessary yet, but I hope over the summer that we will continue to make progress," Odierno told reporters in a teleconference from Iraq.

Odierno acknowledged that the violence had risen again in May compared to April, despite the ongoing US troop increase launched in January.

Meanwhile, the hunt intensified for five Britons who were snatched at gunpoint from a finance ministry building in the capital earlier this week, in an abduction that has been blamed on Baghdad's Shiite militias.

US forces detained two suspects in a raid on Sadr City, the eastern Baghdad bastion of Shiite cleric Moqtada al-Sadr's Mahdi Army, but it was not clear whether this operation was linked to the missing Britons.

Two US soldiers were killed by a roadside bomb on Wednesday in the southwest corner of the capital, a ward of battered neighbourhoods that has seen intense fighting recently. A separate blast that day killed two others on foot patrol.

Another soldier was killed earlier this week by a roadside blast northwest of the capital, and a US soldier died of "non-battle related causes," the military also announced on Thursday.

The latest deaths bring US casualties for the month to 119, the most since November 2004 when marines launched a full-scale invasion to retake the city of Fallujah in the volatile western Anbar province.

Unlike in Fallujah, US forces have fought no major set-piece encounters in May, but instead have been fanning out through Baghdad and a belt of flashpoint towns around the capital in a bid to quell sectarian violence.

"First and foremost, it's been a tough month," Brigadier General Perry Wiggins, deputy director of regional operations with the US Joint Chiefs of Staff, told reporters at a Defence Department briefing on Wednesday.

"We're moving into places where we haven't been, not necessarily before."

April was also bloody for the US-led coalition, with 104 deaths. Taken together, the two past months have been the deadliest since the March 2003 invasion that toppled Saddam Hussein.

The news will increase pressure on US President George W. Bush, who has already seen domestic support for his war strategy fall to an all-time low and is facing calls to set a timetable for troops withdrawals.

May's casualties coincide with a "surge" in US reinforcements, which is due to peak next month. Under this plan, US and Iraqi troops are basing themselves in relatively exposed patrol bases in order to control Baghdad street by street.

US commander General David Petraeus hopes that the surge will provide breathing space for Prime Minister Nuri al-Maliki's government, allowing him to push through laws to underpin a programme of national reconciliation.

The continuing instability of the capital was driven home Tuesday when a squad of gunmen in police uniforms stormed a finance ministry building and dragged off five British visitors.

The Britons are still missing amid fears they have fallen into the hands of one of the Shiite militia groups that have infiltrated Iraq's police.

Violence continued in Iraq, even in Anbar province where recent attacks had declined following a decision by tribes there to fight Al-Qaeda led insurgents.

Six people were killed in Ramadi when a suicide car bomb exploded, apparently targeting the local mobile phone infrastructure.

"A suicide bomber blew himself up near the Iraqna mobile service tower killing six people, including three police guards," said Lieutenant Colonel Jubeir al-Dulaimi.

In nearby Fallujah, which has remained home to a stubborn insurgency, a checkpoint in a northeast neighbourhood was attacked by small arms fire and a man wearing a belt of explosives, killing one policeman.

In the northern city of Kirkuk a bomb killed one person while police in Mosul found five corpses, three in army uniforms.

The US State Department reported two of its Iraqi employees missing in Baghdad days after Al-Qaeda in Iraq issued an unverified statement that it had killed two local US embassy employees.