Iraqi holds remains of US bomb dropped during overnight air strike in Sadr City, 22 Apr 2008

The U.S military in Iraq says its troops killed five militants late Monday in Baghdad's Sadr City district.

A military statement said a U.S. Apache helicopter targeted gunmen carrying rocket-propelled grenade launchers, killing two of them.

In another incident, a group of soldiers shot and killed three militants in response to a roadside bomb attack on a U.S. military vehicle.

Violence has increased in Sadr City, a stronghold of the radical Shi'ite cleric Moqtada al-Sadr, since Prime Minister Nouri al-Maliki began an offensive against Shi'ite militias last month.

In a separate development, a jihadist Web site has released an audio recording of al-Qaida's second-in-command, Ayman al-Zawahiri, answering questions submitted to Internet forums.

In the two-and-a-half hour recording, Zawahiri said the jihad (holy war) in Iraq is most important.

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