BAGHDAD, Iraq -- Sunni militants burned homes in a mixed city northeast of Baghdad on Saturday and yesterday, forcing dozens of families to flee and raising the specter of a new intimidation tactic in Iraq's evolving conflict, Iraqi officials and witnesses said.
Militants also continued their campaign against Shiite pilgrims yesterday, striking as they returned home from the southern city of Karbala after observances for the Arbaeen holiday drew millions of people over the weekend. The worst attack, a car bombing, killed at least 19 people in Baghdad as they were riding home from the south in a pickup.
Attackers burned Sunni and Shiite homes in a neighborhood of Muqdadiya, a city of about 200,000 in Diyala province, about 60 miles from Baghdad. There were differing reports about how many houses were affected. A security official in Diyala said that at least 30 houses were completely burned, including occupied and abandoned buildings, while a Sunni Arab politician from the area said that only six houses were destroyed. Some witnesses said as many as 100 houses were set on fire.
Victims from both sects blamed the Islamic State of Iraq, an umbrella organization for Sunni extremists that has taken over several other towns in the area. Residents said the group had recently demanded money, weapons, and oaths of support from the local populace.
They said the burnings were intended to scare people into giving in or running away. Dozens of families fled the city, either left homeless by the attacks or terrified that they would be next.
"I left everything behind because I didn't want to contribute to harming other Iraqis," said Abu Muhammad Khailani, a Sunni, who said he escaped to a Shiite village for protection.
"I know why they want the money and weapons," he said. "They will kill innocent people and do whatever it takes to reach their goals."
The attacks reignited fears that Iraq is being hollowed out by efforts in some areas to drive out those who do not support an extremist sectarian agenda. Many mixed neighborhoods of Baghdad have been transformed into homogenous enclaves, with Shiites and Sunnis issuing death threats to the minority sect and even to those who intermarry or maintain cross-sectarian friendships.
Two other explosions in Diyala province, both near Baqouba, killed at least five people and injured 13 yesterday.
Even before the house burnings over the weekend, Diyala had become a caldron of daily violence, with American and Iraqi forces fighting a growing Sunni threat that has often overwhelmed the province's Shiite leaders. Residents report that in some villages, the Islamic State of Iraq brazenly flies flags that declare loyalty to Abu Omar Al-Baghdadi, the group's leader, in what appears to be both a warning and a taunt to the group's opponents.
American military officials have said they are increasingly concerned about the area's slide into chaos. The American commander for northern Iraq, Maj. Gen. Benjamin R. Mixon, said this week that he had already shifted additional troops to the province and asked for extra reinforcements.
On Thursday, Gen. David H. Petraeus, the top American commander in Iraq, said Diyala would "very likely" get more troops as part of an increase concentrated in Baghdad.
The Baghdad police said that the 19 Shiite pilgrims were killed yesterday in the mostly Shiite area of Karada when a car bomb exploded next to their truck. They were on their way home from Karbala, where they observed Arbaeen, which marks the end of a 40-day mourning period to commemorate the killing of Imam Hussein, the Prophet Muhammad's grandson.
Witnesses said a silver Hyundai sedan parked on the side of the road exploded when the truck passed. Mustafa Mahdi Sahed, the truck's driver, who survived without serious injury, said the blast tore through his passengers, turning their cooking pans into shrapnel and bloodying the posters they had carried to honor the martyr Hussein. Sitting on a curb by his destroyed vehicle hours after the blast, he said he had driven the pilgrims home from Karbala for free. In contrast, he said he had heard that suicide bombers or their families get paid to kill.
"Is it worth it to sell Iraqi lives for $200 or $300?" he said.
In the same neighborhood yesterday, a roadside bomb killed one person. And just west of Sadr City, the sprawling Shiite district in northeast Baghdad, a suicide bomber on a minibus set off his explosives near a restaurant, killing at least 10 other people and injuring eight, an Interior Ministry official said.
In Adhamiya, a nearby Sunni neighborhood, a remotely piloted American reconnaissance aircraft crashed. An American military spokesman said the drone was recovered intact. He would not say whether it had been shot down.
The U.S. military also said in statements that three American soldiers died yesterday in Baghdad, Salahuddin province and northern Iraq.