Syrian Extremist Rebels Raid Shiite Village Syrian rebels, including Sunni extremists, stormed a village and battled pro-regime militiamen, killing more than 60 Shiite fighters and civilians in an attack steeped in the sectarian hatreds that increasingly characterize the civil war, activists said Wednesday. In the raid, which comes at a time when the West is worried that extremists are increasingly joining the rebellion, the victorious fighters raised black Sunni Islamist flags over the eastern village of Hatla. In amateur videos, the fighters - some wearing al-Qaida-style headbands - vented anti-Shiite slurs and fired in the air. "The homes of the infidel Shiites were burned," the voice behind the camera in one video shouted as smoke rose in the background from several houses. In another video, the fighters pulled blankets off corpses to show them off, one with a wound to the head. A gunman talking to the camera gloated, saying, "This is your end, dogs." The videos appeared genuine and conformed with other Associated Press reporting on the events depicted. The attack Tuesday on Hatla, in Syria's Deir el-Zour region near Iraq, underlined the increasingly sectarian nature of the conflict. The regime called it a "massacre," and some opposition members expressed concern about the nature of the attack. The U.S. and other Western nations have been hesitant to arm the outgunned and outmanned rebels because of Sunni jihadi radicals among their ranks. State Department spokesman Jen Psaki said the U.S. was "appalled by reports that rebels have killed 60 Shia in Hatla village." "The motivations and circumstances surrounding this massacre remain unclear, but the United States strongly condemns any and all attacks against civilians," Psaki said. The uprising began more than two years ago with peaceful protests against President Bashar Assad but later grew into a civil war that has killed more than 80,000 people. In the past year, sectarian bitterness has grown in the conflict. Each sect has been accused of massacres against the other, and Sunni and Shiite fighters from other countries have increasingly joined the battle. But the sense of the fight being a battle between faiths was taken up a notch after Shiite guerrillas from Lebanon's Hezbollah helped Assad's forces take the rebel stronghold of Qusair last week. Some fighters in Hatla can be heard in the video calling the attack "the first revenge for Qusair." The town is home to several thousand people, about 30 percent of them Shiites, and was considered a pro-regime community in the Euphrates River valley, where rebels - including the al-Qaida-linked group Jabhat el-Nusra - have taken over much of the territory. Rebels launched a counterattack Tuesday, said the activist, Thaer al-Deiry, who identified himself only by his nickname for fear of government retaliation, via Skype. He said some 150 Shiites from the village fled across the Euphrates to the government-held village of Jafra.