U.S. troops backed by aircraft early on Thursday raided Baghdad's eastern neighborhood of Sadr City, killing three insurgents and injuring three civilians, the U. S. military said.

The raid targeted suspected members of "secret cell terrorist network" known for facilitating the transport of sophisticated roadside bombs from Iran as well as bringing militants from Iraq to Iran for training, the military said in a statement.

According to intelligence reports, the cell has ties to a kidnapping network that conducts attacks within Iraq, added the statement.

According to the statement, three armed men were killed when troops called for close air support to end a gunbattle with militants holed in two buildings in the area, which is a stronghold for militiamen loyal to the radical Shiite cleric Muqtada al-Sadr.

"During the course of the morning's operations, Coalition Forces targeted a concentration of buildings associated with the terrorist network, detaining four suspected terrorists during the raids," the statement said.

The operations also resulted in the injuring of three Iraqi civilians, it added.

The U.S. military frequently accused Iran of providing Iraqi Shiite militia with weapons and parts for sophisticated armored- piercing bombs, which has been denied by Iran.

U.S. and Iraqi security forces have staged a security plan in the capital since Feb. 14 with an aim of putting rampant violence under control.

Source: Xinhua