Iraq's most senior Shiite Muslim cleric urged followers to take up arms against a full-blown Sunni militant insurgency to topple Shiite Prime Minister Nouri al-Maliki, a conflict that threatens civil war and a possible break-up of the country.
In Washington, U.S. President Barack Obama said he was reviewing military options, short of sending combat troops, to help Iraq fight the insurgency but warned any American action must be accompanied by an Iraqi effort to bridge political divisions.
In a rare intervention at Friday prayers in the holy city of Kerbala, a message from Grand Ayatollah Ali al-Sistani, the highest religious authority for Shiites in Iraq, said people should unite to fight back against a lightning advance by militants from the radical Islamic State of Iraq and Syria.