Hospitals say they are struggling to cope with the casualties
More than 400 people have been killed in fighting over the last month between Shia militias and US and Iraqi forces, hospital officials in Baghdad say.
The fighting has been concentrated in the capital's eastern district of Sadr City, a stronghold of the Mehdi Army militia of the cleric, Moqtada Sadr.
Five US soldiers have been killed in fighting in Baghdad since Tuesday.
April has been the most lethal month for US troops in Iraq, with 49 deaths, since September, when 65 soldiers died.
The US military said two soldiers were killed on Wednesday afternoon in southern Baghdad when a bomb exploded near their patrol. A third was killed by a roadside bombing overnight in the north.
Two US soldiers were killed in the north-west of the city on Tuesday evening in separate attacks. The first died when he came under small-arms fire, while the other was killed by a roadside bomb.
The large number of casualties came after US and Iraqi forces launched an offensive in March to disarm militias in Baghdad and the southern city of Basra.
The clashes in the capital flared up again on Sunday after militia members attacked coalition positions during a sandstorm.
Many civilians have been caught up in the Baghdad clashes
The US military said at least 28 militants were killed during battles in the Sadr City area of the capital on Tuesday, while four US soldiers were killed by rocket and mortar fire in the east of the capital on Monday.
Doctors said more than 50 civilians were injured in the fighting on Tuesday.
The two main hospitals in Sadr City are struggling to cope with the recent influx of casualties, officials at the Imam Ali and the Sadr General hospitals have said.
More than 400 people have died and almost 2,500 others have been injured since the end of March, they added.
Staff at the hospitals are worried they are running out of clean water and do not have enough severe trauma specialists to treat all those who need help.
An Iraqi government spokesman, Tahsin al-Sheikhli, later said as many as 925 people had died in the Sadr City fighting, but he gave no timeframe or further details about how the figure was reached.
An independent website, icasualties.org, estimates that 4,058 US soldiers, and 310 soldiers from other nations, have been killed in Iraq since the 2003 invasion.
Another website run by academics and peace activists, iraqbodycount.net, reports that 90,782 Iraqi civilians have been killed in the same period.
Later, Iraqi Prime Minister Nouri Maliki vowed not to ease the military offensive until all militias, both Sunni and Shia, were crushed.
Speaking at a news conference in Baghdad, he said the militias were no better then al-Qaeda because they brought instability and destruction to Iraq.
Last week Moqtada Sadr told his supporters that while they should continue "resisting" what he called the US "occupation", they should not fight Iraqis. He also rejected the government's demands.
The BBC's Clive Myrie in Baghdad says this is the first time the prime minister, himself a Shia, has tried to crush the Shia militias.
Intense pressure from the Sunni and Kurdish members of his government, and behind the scenes from the US government, has helped force his hand, our correspondent says.
In the eyes of some, Mr Maliki is finally being seen as a leader of all Iraqis, not just the Shia majority, he adds.