Gunmen in northern Iraq have assassinated the deputy police chief of Mosul.
Authorities say several attackers in a car opened fire on Brigadier Hikmat Mohammed as he drove to work this Wednesday morning.
Hours earlier, a previously unknown militant group distributed leaflets near a police station in the northern city of Kirkuk, threatening attacks on police or anyone else found cooperating with U-S forces.
Hundreds of police officers and other Iraqis working with the U-S-led coalition have been killed in suicide attacks throughout the country over the past several months.
Elsewhere, a U-S military helicopter has crashed in a river in western Iraq, killing two crew members.
The U-S military command in Baghdad says the crash, about 200 kilometers northwest of the capital, appears to have been caused by mechanical failure.
In other developments, United Nations' special envoy Ross Mountain has arrived in Baghdad to assess humanitarian needs ahead of a weekend donor conference on post-war Iraq.
Mr. Mountain was appointed to his position following the death of former special U-N representative Sergio Vieira de Mello. Mr de Mello and 21 other people were killed last August in a truck bombing on U-N headquarters in Baghdad.