Iraqi men carry an injured man as a US soldier secures the area, after a car bomb explosion, in Ash Sha'b neighborhood, northern Baghdad, 4 June 2008

The U.S. military says a Shi'ite militia rocket accidentally exploded in the Iraqi capital, killing 18 people.

However, Iraqi police say the explosion Wednesday was caused by a truck bomb that destroyed the home of a top Iraqi police officer. They say the officer was not hurt, but that his nephew was among those killed.

Officials say at least 65 people were wounded in the explosion

Separately, police say a car bomb exploded in the Baghdad's Jadiya neighborhood, killing four people and wounding at least nine.

In other news, the U.S. military says at least 23 bodies were found in a water-filled mass grave in Baghdad. Officials say the remains appear to be two years old.

The military also says a gunfire attack killed three U.S. soldiers near the northern city of Kirkuk. It did not provide further details.

The U.S. military says coalition forces detained nine suspected al-Qaida in Iraq militants in operations across central and northwestern parts of the country today.

A statement says the troops disrupted al-Qaida in Iraq bombing networks with the capture of four suspects in operations in and near Baghdad.

Some information for this report was provided by AFP, AP and Reuters.