In a statement received by Aljazeera, the imams called for Muslim scholars to issue a fatwa (decree) allowing for civil disobedience and a sit-in in Falluja.
They called for the interim Iraqi government to take a clear stance and not accept the "al-Zarqawi lie", used as an excuse to kill innocent women and children in the city.
Falluja has come under repeated US air strikes over the past few weeks. The US says it is targeting hideouts and meeting places of supporters of Abu Musab al-Zarqawi.
The clerics' statement added that, should the government not heed the appeal, then a call would be made for jihad and a general mobilisation of fighters would begin.
Tens of Iraqis have been killed in missile attacks on Falluja.
UK troop redeployment
British troops serving in the south of the country could soon be heading to Baghdad to cover for US soldiers battling anti-American forces in Falluja and elsewhere in Iraq.
There has been no official word
regarding British troops in Baghdad
The deployment to the Iraqi capital would be the first time British troops have operated outside the Basra area of southern Iraq.
Up to 650 troops would be involved in the move, which would last for just a few weeks, the BBC reported.
A ministry of defence spokesman in London said no decision had been made and that any significant movement of troops would be announced "in the normal way".
The Times newspaper said officers from Britain's Black Watch regiment, currently serving in Basra, had told their troops about a possible move to Baghdad.