Correction: An earlier version of this story reported that the pilgrims were traveling to Syria. They were coming from Syria.

Gunmen hijacked a bus of Shiite pilgrims traveling through a Sunni area in western Iraq late Monday and killed 22 of the captives, officials said.

A government spokesman said the tour bus of pilgrims from Karbala on their way from a holy shrine in Damascus, Syria, had entered a desolate valley west of Ramadi when gunmen set up a fake checkpoint and hijacked the vehicle. As the Iraqi military launched a helicopter search, the tour group was taken into the desert, and 22 men aboard were fatally shot, a military spokesman said.

Security forces found eight women and six children alive and took them to a hospital for treatment, said Gen. Abdul Aziz al-Ubaidi, commander of the Iraqi military in Anbar province.

The Associated Press reported that authorities were questioning a suspect found with weapons in his car near the hijacking location.

On Tuesday, religious leaders blamed the attack on Sunni insurgents hoping to revive sectarian violence as U.S. troops prepare to leave the country at year’s end.

Anbar province, where the hijacking occurred, was once one of the most dangerous areas of Iraq. Violence has lessened in recent months, but it remains a focal point of activity for Sunni insurgent groups, including al-Qaeda in Iraq. On Aug. 25, 15 people, most of them police officers, were killed in a series of attacks there.

Mohammad Fathi Hantush, a spokesman for Anbar’s provincial government, said the tour bus had chosen a risky route and was traveling at night through a stretch of byway that was “dangerous during the daytime, let alone at night.”

Special correspondents Uthman al-Mokhtar in Fallujah and Saad Sarhan in Najaf contributed to this report.