BAGHDAD - Five US soldiers were killed in Baghdad over the weekend, the military said on Monday, taking the number of American soldiers killed in Iraq this month to more than 100.

US Army Pfc. Casey Legrande, 21, from Norman, Okla., left, and Staff Sgt. Avila-Portillo, 25, from El Paso, Texas of Delta Co., 2nd Battalion, 7th Cavalry Regiment, 4th Brigade, 1st Cavalry Division, patrol in northern Mosul, Iraq Sunday, April 29, 2007. [AP]

That makes April one of the deadliest months for US forces in Iraq since the US-led invasion in 2003.

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The April toll could increase the pressure on US President George W. Bush, who is fighting a plan by Democrats to set a timetable for withdrawing US forces from Iraq.

The US military said in a statement that three soldiers had been killed by a roadside bomb in eastern Baghdad on Sunday. An Iraqi interpreter was also killed in the attack.

A separate statement said one soldier was killed by small arms fire also in eastern Baghdad on Saturday.

US and Iraqi forces launched a major security crackdown in Baghdad in mid-February that is seen as a final attempt to halt Iraq's plunge into all-out sectarian civil war among Sunnis and Shi-ites.

US commanders acknowledge that the offensive, which has led to the deployment of thousands of extra troops on the streets, has increased the risk of military casualties. Many of April's casualties were in Baghdad.

Before the announcement of the latest deaths, the independent icasualties.org Web site had put the number of US troops killed in Iraq in April at 99.

More than 3,330 US troops and many tens of thousands of Iraqis have been killed since 2003.

Bush has vowed to veto a war spending bill from Democrats that requires combat troops to begin withdrawing by Oct 1. The Democratic-controlled Congress plans to send the bill to Bush on Tuesday.

The political battle in Washington is being exploited by al Qaeda, which has stepped up attacks to hasten a withdrawal, Iraqi Foreign Minister Hoshiyar Zebari told Reuters on Sunday.

He said Iraq had become "entangled" in domestic politics in America, where there is growing impatience for progress in reconciling the country's warring sects.

In a breakthrough for Iraq, Iran said on Sunday it would attend a ministerial conference of key powers including the United States this week in Egypt that will focus on stabilizing Iraq.

Zebari said there was a "high possibility" Tehran and Washington would hold bilateral talks at the May 3-4 conference in Egypt, although not necessarily at the ministerial level.

Washington accuses Iran of destabilizing Iraq, a charge Iran denies.

The announcement of Iran's participation followed weeks of intense lobbying by Baghdad, which had sought to persuade Iran to take part despite Tehran's anger over the detention by US forces of five Iranians in northern Iraq in January.