U.S. Special Operations forces conducted a large-scale counterterrorism raid on a two-story house in Syria’s northwest Idlib Province early Thursday, in pursuit of what one U.S. official told The New York Times was a “high value” target. The Pentagon gave only cursory details of the raid, near Atmeh, a town near the Turkish border. Local aid and monitoring groups said at least 13 bodies were recovered from the wreckage, including some women and children. 

“The mission was successful,” Pentagon spokesman John Kirby said in a statement released early Thursday. “There were no U.S. casualties. More information will be provided as it becomes available.”

Residents of Atmeh said U.S. helicopters flew in low a little after 1 a.m. local time, and a man speaking Arabic said through a loudspeaker that the house was surrounded and women and children should evacuate. “This went on for 45 minutes,” nearby resident Omar Saleh told The Associated Press. “There was no response. Then the machine gun fire erupted.” 

After “a long, tense standoff,” the Times reports, “a major battle erupted, with rocket-propelled grenades and other fire hurtling from the house and surrounding buildings toward the Americans.” A U.S. helicopter malfunctioned and had to be blown up on the ground. A senior U.S. military official told the Times there was also an explosion inside the house caused not by U.S. firepower but more likely by the target of the raid blowing himself up. After about two hours, the U.S. forces left in the remaining helicopters.

“The size, scope, and duration of the battle suggested that the target of the raid was likely a senior Qaeda figure,” the Times reports. “The fact that the United States risked sending in commandos, and not just launching airstrikes, also suggested the focus of the raid was a senior figure.” U.S. officials said they could make an announcement as early as Thursday, following a DNA analysis.

The Syrian Civil Defense, a first responder group known as the White Helmets, and Britain-based Syrian Observatory for Human Rights monitoring group both said 13 people were killed, including at least four children and two women. A spokesman for the White Helmets said the group “cannot determine whether there were bodies that were retrieved by U.S. forces because there is blood everywhere.”