A deal to end fighting in Baghdad's Sadr City district is reported to be holding.
Gunmen have left the streets after weeks of battles between Shi'ite militants and U.S.-backed Iraqi government forces.
Fighting in Sadr City has killed hundreds of people since late March when Iraq's Prime Minister Nouri al-Maliki ordered a crackdown on Shi'ite militias.
Iraqi Shi'ite political factions reached the ceasefire deal on Saturday.
The U.S. military said it would scale back operations to see if gunmen obey the truce.
An Iraqi government spokesman says militias must put away their weapons and accept that government alone has responsibility for security.
He says the truce for Sadr City also gives security forces the right to search any place suspected to be a weapons storehouse.
Elsewhere in Iraq, U.S. forces killed two gunmen and two civilians near the northern city of Mosul on Saturday.
The U.S. military said its forces were following suspected associates of an al-Qaida in Iraq terrorist and fired on a vehicle, killing two armed men, a woman and a child. The military says it regrets the deaths of the civilians.
U.S.-backed Iraqi forces on Saturday began a major operation in Mosul against al-Qaida in Iraq. The city is considered the group's last significant urban stronghold.
Some information for this report was provided by AFP, AP and Reuters.