BAGHDAD -- A forbidden love affair that ended in a young woman's death by stoning led to religiously motivated bloodshed yesterday when gunmen dragged members of a tiny religious minority off a bus and killed 21 of them, Iraqi police and witnesses said.
The incident in the northern city of Mosul was shocking in its brutality and frightening for the specter it raised - violence between Muslims and non-Muslims, aggravating the already volatile conflict involving Sunni Arabs and Sunni Kurds.
Baghdad also was rocked by violence yesterday. Two car bombs killed at least 19 people in the capital. One explosion targeted a police station being used as temporary quarters for officers whose station was destroyed in a bomb blast.
In all, at least 72 people were killed or found dead in Iraq yesterday, including 24 bullet-riddled bodies and two brothers who were shot to death in the volatile city of Fallujah, a day after the chairman of the city's council was assassinated.
The victims of the Mosul attack were Yazidis, a sect that is neither Christian nor Muslim and whose followers have faced persecution from a succession of rulers.
Police in Mosul said the killings of the Yazidis took place yesterday evening as a bus was carrying employees of a weaving factory home after work. Men in two sedans blocked the road on which the bus was traveling, then separated the Yazidis from other passengers before shooting them, said police Capt. Ibrahim Jaboori.
Police and residents of Bashiqa, home for many of the victims, linked the attack to the stoning death this month of a Yazidi woman by fellow Yazidis angry over her conversion to Islam and love affair with a Sunni Arab. The stoning occurred in Bashiqa, they said, about 20 miles north of Mosul.
Ayad Arshad, 17, a student who was nearby, said people panicked and fled into their homes. After it was over, Arshad emerged from his house to see bodies strewn on the ground.
"Most of them were older people. Only two were about my age," he said. "The scene was disgusting. It reminded me of what my father told me about the genocides that Saddam [Hussein] used to do."
The killings struck terror among Yazidis, who closed their shops and braced for further attacks.
"People ran in fear, hiding in their houses," said Aydan Sheikh, a Yazidi from Bashiqa. "Bashiqa is like a ghost town."
The killings raised the specter of a new crisis in Mosul, where Kurds and Sunni Arabs are vying for dominance in an increasingly bloody ethnic conflict.
This month, the U.S. military announced that the security crackdown that was supposed to focus on Baghdad and neighboring Anbar province would be extended to Mosul, 225 miles north of the capital, because of violence there.
A Sunni Arab politician in Mosul blamed the shootings on insurgents trying to foment religious violence.
"A week ago when they killed the girl that converted to Islam, it was a hideous crime," said Yahya Mahmood. "However, this is not justification for what happened today. This incident is a conspiracy against Mosul to incite civil war."
The London-based Minority Rights Group estimated in February that the Yazidis numbered 550,000 in Iraq before March 2003, but that many had fled since the war began because of rising religious and ethnic tensions.
In other developments, a U.S. military plan to wall off a volatile Baghdad neighborhood appeared on the verge of collapse after Prime Minister Nouri al-Maliki joined the chorus of complaints about the project, which critics say would worsen relations between Sunni and Shiite Muslims.
The 12-foot-high wall began going up around the Sunni area of Adhamiya on April 10 as part of a U.S.-Iraqi security plan to quell sectarian warfare in Baghdad. The U.S. military had portrayed it as the best method of stopping violence in Adhamiya, which is surrounded by Shiite neighborhoods.
The U.S. military also announced the deaths of four American troops. They included a Marine killed when a base southwest of Baghdad came under fire Saturday night and a soldier killed Saturday in western Baghdad when a patrol was attacked by small-arms fire and rocket-propelled grenades. On Friday, a Marine died during fighting in western Anbar province. Another soldier died Saturday of noncombat causes, the military said.
Tina Susman writes for the Los Angeles Times. The Associated Press contributed to this article.