By Andrew North
BBC correspondent in Baghdad
Boycott calls, accusations of a massacre or of evidence being faked, and now a presidential inquiry.
The mosque complex lies in a stronghold of Moqtada Sadr
A weekend raid by US-backed Iraqi special forces has sparked some unusually bitter exchanges between Iraq's politicians and the Americans.
In response, Baghdad's provincial council says it is suspending co-operation with both the US military and embassy.
Talks on forming a new government were briefly suspended and Iraq's president has ordered an investigation into the incident.
But many believe the key to the row is the increasing tension between the US and Iraq's dominant Shia political bloc - who have led the charges against the Americans
Shia leaders have accused the Iraqi and US troops of massacring unarmed worshippers in a mosque - all of them believed to be Shia. One minister has said 37 unarmed men were killed.
The US military says no mosque was entered or damaged during the raid, which it says was carried out on a compound by 50 Iraqi special forces backed up by 25 American advisors.
In a statement, it said 16 people it describes as insurgents were killed and an Iraqi man held hostage there was freed.
TV footage and still photos showed scenes of bloody carnage
US officials also say another 18 people were detained, and there are reports one of them is a senior figure in the Mehdi militia loyal to the radical anti-American cleric Moqtada Sadr
Graphic footage shown on Iraqi TV channels of the bodies of men lying close together, apparently unarmed, have further fuelled concerns over the incident. But the Americans have suggested the scenes were faked.
"After the fact, someone went in and made the scene look different than it was," said Lt General Peter Chiarelli, the number two US commander in Iraq, when asked about accusations unarmed people in a mosque had been killed.
There has been confusion too over who controls the shadowy Iraqi force involved.
The Iraqi defence ministry has denied knowledge about the operation. But the Americans insist the operation was co-ordinated with senior Iraqi military officials.
Many previous US operations have sparked controversy, but rarely have they generated this kind of political heat.
Some have also pointed out the contrast between the quick and vocal reaction to this incident and the lack of response from Iraqi politicians to the daily discovery of bodies around the capital, most of them believed to be victims of the continuing sectarian strife between Shias and Sunnis.
Many see this row as more about politics, at a time when months-old negotiations on forming a government between the Shias and other political groups are at a sensitive point - negotiations in which US diplomats are closely involved.
One Iraqi source with knowledge of the talks believes it is no coincidence that the first reaction of several Shia political figures to the disputed raid was to call for the Americans to hand over control of security matters to the Iraqi authorities.
"On that same day, the United Iraqi Alliance had been pushing for full control of security issues," the source said, referring to the main Shia political coalition. "That has been the key sticking point".
But UIA figures insist their reaction is motivated by concern over what took place, not politics.
"Witnesses confirm to us that the people were praying in a mosque when they were attacked," said Dr Haider al-Abadi, an adviser to Prime Minister Ibrahim al-Jaafari who is the UIA candidate to continue in the position.
"Why did the defence ministry deny any involvement?" he asked.
Anguished relatives buried the dead the following day
Another Shia figure, who asked not to be named, questioned American statements that an Iraqi dentist who had been taken hostage had been rescued.
"We are amazed by this," he said. "If someone had been kidnapped, why did the Iraqi police not know?"
But Dr Abadi admits the Shia alliance does feel under pressure from the Americans right now.
Shia leaders are not seeking confrontation, he said, but "politically, we cannot be seen to be complacent at the moment."
"If you look at the political and the security front, they [the Americans] are tightening the screw on just one side."
It is not clear how long this inquiry ordered by President Talabani to look into the raid will take.
But many see it as aimed more at reducing tensions over the incident, rather than being a comprehensive effort at finding out what happened.