Kut, Iraq ? Ukrainian soldiers fired into the air Monday to disperse hundreds of Iraqis who rioted for jobs and food as a second southern Shiite Muslim city was rocked by unrest — a barometer of rising frustration with the U.S.-led occupation in a region of Iraq considered friendly to the Americans.

Also Monday, a roadside bomb in the capital killed one American soldier and wounded two, bringing the U.S. death toll in the Iraqi conflict to 495. Large explosions rocked central Baghdad later in the day, but officials reported no casualties.

Trouble started in Kut, 95 miles southeast of Baghdad, when about 400 protesters marched for a third straight day on a government building to demand jobs. Someone in the crowd threw a grenade at police and Ukrainian soldiers guarding the building, injuring four Iraqi policemen and one Ukrainian, according to Lt. Zafer Wedad.

Demonstrators also hurled bricks at the building and trashed a post office in the city.

In a similar protest Sunday in Amarah, waves of protesters rushed British troops guarding the city hall before being pushed back. On Saturday, clashes in Amarah killed six protesters and wounded at least 11.

Unrest in the Shiite areas has spread as the country’s leading Shiite cleric, Grand Ayatollah Ali al-Husseini al-Sistani, has spoken out against the U.S.-backed formula for transferring power to the Iraqis.

In a full-page newspaper advertisement Monday, al-Sistani repeated his demand that a proposed provisional legislature be elected rather than chosen by regional committees as called for under a plan endorsed by the U.S.-led coalition and the Iraqi Governing Council.