Ahmed Hussein Khudeir, a taxi driver in the city of Samarra, lined up at 6:30 Saturday morning to wait for gasoline, part of life's maddening routine in oil-rich, gas-short Iraq.

Four hours later, he was still in line when a pickup truck barreled toward the gas station in the wrong lane. A young man in a black headdress rammed the pickup into a tanker truck at the station just as he exploded a suicide bomb, creating a fireball that killed three and reached Khudeir with its flames.

"They want to destroy the peace," said Khudeir's father, who stood distraught and helpless at a hospital bedside as his 22-year-old son, writhing in pain, recalled what happened. At least eight others were severely burned, according to Mustafa Hussein Bazi, a physician who confirmed the death toll.

The attack on the gas station in Samarra, about 65 miles north of Baghdad, was one of two bombings Saturday in Iraq; the other killed four people when explosives in a parked car detonated as two armored cars passed in downtown Baghdad. Such armored cars often carry foreigners, but the victims this time were Iraqi pedestrians, according to police.

In southern Iraq, police said they found the body of a Sunni Muslim cleric who had been abducted from his home in Basra Friday evening by gunmen. Sheik Nadir Karim was the second Sunni religious figure killed in Basra in the past seven days, increasing fears of sectarian warfare between Sunnis and Shiites as the country moves toward Dec. 15 elections.

Karim had been shot many times and dumped in an old British cemetery, according to Basra police Capt. Raji Hassan.

The Sunnis, who wielded power during Saddam Hussein's rule, and the majority Shiites, who control the government now, have traded deadly attacks. A group claiming to represent Sunnis claimed on a Web site Friday that it had carried out a car bombing in the southern Shiite city of Hilla that killed 11 people Thursday.

The group, calling itself Partisans of the Sunni, said in a statement that it had conducted the attack to retaliate for the slaying of Sunni cleric Khadim Sarhid Hemaiyem in Baghdad on Wednesday. Gunmen wearing Iraqi army uniforms broke into Hemaiyem's home, killing the cleric, his three sons and a son-in-law.

"We have warned the [Shiites] to stop assassinations and detentions and torture," the statement said. "You should know, your blood is no more dear than ours. You kill our men, we kill yours. You kill our sheiks, we kill yours. You started this war."

The U.S. military said in a statement Saturday that a raid on a home last month in Ramadi, 60 miles west of Baghdad, had killed a top aide to Abu Musab Zarqawi, the Jordanian Sunni radical who leads al Qaeda in Iraq.

The military said "a close family member" and other sources confirmed the death of Bilal Mahmud Awad Shebah, also known as Abu Ubaydah, in the raid. The statement described the man as the "executive secretary" for Zarqawi, saying he met Zarqawi often and served as his "gatekeeper and messenger." U.S. and Iraqi authorities have long and unsuccessfully pursued Zarqawi, who has asserted responsibility for numerous beheadings and other spectacular attacks on U.S. and Iraqi targets, including Shiite civilians.

U.S. military officials also confirmed Saturday that a U.S. Marine was killed Friday in a roadside bombing near Hit, nearly 100 miles west of Baghdad. The Marine's name was not released.

Aldin reported from Samarra. Special correspondent Saad Sarhan in Najaf contributed to this report.

A car bombing in Baghdad attracts the attention of local children. The parked car was detonated as two armored vehicles passed by. The explosion killed four Iraqi pedestrians.