Iraqi Prime Minister Nuri al-Maliki says his government must be involved in the investigation into allegations U.S. soldiers raped an Iraqi teenager and killed her and three family members.
Mr. Maliki said Wednesday his government will reconsider the immunity granted to coalition troops.
A U.S. federal court in the southern state of North Carolina on Monday charged a former U.S. Army private with murder in the case. Other American soldiers also are under investigation.
Separately, a group claiming to have kidnapped a Sunni lawmaker, Tayseer al-Mashhadani, has issued demands for her release.
An unnamed group demanded Wednesday the lawmaker's party, the Iraqi Islamic Party, call for a timetable for the departure of coalition troops, the release of Iraqi detainees and an end to Sunni attacks on Shi'ites.
In Baghdad, a car bomb killed six people and injured at least 14 others.
A U.S. military spokesman said the U.S. expects the number of car and truck bombs to increase. The spokesman said the new al-Qaida in Iraq chief, Abu Ayyub al-Masri, is an expert in vehicle-borne explosives.
In other news, U.S. and Iraqi forces raided a hospital in Ramadi that they said has been used by insurgents as a haven to launch mortar and sniper attacks.
A statement says the combined force found one weapons cache with bomb-making material. There were no reports of civilian or military injuries resulting from the search. Ramadi is an insurgent stronghold west of Baghdad.