Updated

Gunmen ambushed a group of travelers at a fake checkpoint at a remote desert site in western Iraq on Wednesday and killed at least 14 of them, according to Iraqi officials, in what appeared to be the latest blow in sectarian violence gripping the country.

The gunmen, apparently looking for Shiites to kill, struck near the town of Nukhaib, the site of a desert crossroads west of the Shiite holy city, Karbala, in the Sunni-dominated Anbar province.

The gunmen at the fake highway checkpoint checked the identities of travelers, presumably to identify their sect based on their names, according to officials. Police said they found blood-stained IDs on the ground identifying some of the dead as coming from Karbala, 100 kilometers (60 miles) south of Baghdad.

Officials said the 14 victims of Wednesday's attack were shot in the head. They said the dead included police and soldiers, as well as civilian residents of the overwhelmingly Shiite Karbala.

The officials spoke on condition of anonymity because they were not authorized to release the information to reporters.

Mohammed al-Moussawi, a provincial councilman in Karbala, confirmed that four of the dead ambush were civilians from the province.

The area around Nukhaib, near where Wednesday's attack happened, was the site of a deadly September 2011 ambush on a bus carrying Shiite pilgrims.

There was no immediate claim of responsibility for Wednesday's attack. Iraqi officials believe Sunni insurgents including al-Qaida's Iraq branch as well as loyalists of Saddam Hussein's former regime are responsible for much of the violence against Shiites and government security forces, which are dominated by the Muslim sect.

The attack came at the end of a Shiite commemoration of a revered eighth century saint believed to be buried in Baghdad. Authorities imposed tight security measures in the Iraqi capital to protect pilgrims, and no serious violence was reported there during the commemoration.

Violence has spiked in Iraq in recent weeks, raising fears of a return to widespread sectarian bloodshed.

According to the United Nations, at least 1,045 Iraqi civilians and security personnel were killed in May. The tally surpassed April's 712 killed, making May the deadliest month recorded since June 2008.

Iraq witnessed its bloodiest bout of violence between 2006 and 2007, when the country was on the brink of civil war and armed men freely roamed the streets of Baghdad.

Killers frequently used victims' names to identify them as Sunni or Shiite at the height of the conflict, and forgers sold fake ID cards bearing false names identified with a particular sect.

At the peak of the sectarian violence between Shiites and Sunnis, more than 3,000 people died each month.