Baghdad, Iraq ? Suicide bombers, one dressed as a woman, blasted worshippers as they left a Shiite mosque after Friday prayers, killing at least 79 people and wounding more than 160 in the deadliest attack in Iraq this year.

The horrific explosions at the Buratha mosque are likely to stoke the already raw tensions between Shiite and Sunni Muslims. The U.S. ambassador warned in an interview published Friday that sectarian civil war in Iraq could inflame the entire Middle East.

Rescuers raced to and from the mosque, ferrying bodies from the walled compound on blood-soaked wooden pushcarts and loading them on the beds of pickup trucks. City officials urged Iraqis to donate blood for the wounded.

Inside the mosque, blood stained the chipped and crumbling floor next to a red prayer rug and spattered the dingy white walls of a nearby corridor, where a cupboard and plates lay shattered. A firefighter wearing a yellow helmet and yellow gloves kneeled down to inspect the scene in the main prayer room.

Police said there were two suicide bombings at the mosque, and an Associated Press photographer saw evidence of two blasts – one at the outer wall surrounding the compound and another at the entrance to the mosque building. The blast in the entrance likely killed some worshippers inside.

Mainstream Sunni Arab politicians condemned the bombings, calling on all religious and political leaders to come together in the interest of national unity.

“Bloodshed is forbidden,” Sunni lawmaker Adnan al-Dulaimi told Iraqi television.

Also Friday, the U.S. military reported the deaths of four more American service members, including one who died from wounds suffered in Baghdad. Two Marines and a soldier were killed Thursday.