Sunni Arab leaders in western Iraq have condemned a joint U.S.-Iraqi offensive in the region, saying it endangers civilians.

The U.S. military launched Operation Steel Curtain early Saturday to restore security along the porous Iraqi-Syrian border and destroy the al-Qaida in Iraq network operating in the area.

Some Sunni Arab politicians and tribal leaders complained that the operation endangers civilians and could lead to greater instability in Sunni sections of the country.

Residents of the town of Husaybah, 320 kilometers northwest of Baghdad, say thunderous explosions shook the town as some 2,500 U.S. troops and 1,000 Iraqi soldiers fought their way through the town.

Elsewhere, at least 11 people were killed when gunmen ambushed a minibus in Balad Ruz, 60 kilometers northeast of Baghdad.

Also, the U.S. military said at least three more soldiers have been killed in separate incidents across Iraq.

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