BEIRUT (AP) — The U.N. said today that entire families were shot in their homes during a massacre in Syria last week that killed more than 100 people, including children. Most of the victims were shot at close range, the U.N. said.

Rupert Colville, a spokesman for the U.N. High Commissioner for Human Rights, said the conclusions were based on accounts gathered by U.N. monitors and corroborated by other sources. He said U.N. monitors found that fewer than 20 of the 108 people killed in the west-central area of Houla were killed by artillery fire.

“Most of the rest of the victims were summarily executed in two separate incidents,” Colville told reporters in Geneva. “At this point, it looks like entire families were shot in their houses.”

He said witnesses blamed pro-government thugs known as shabiha for the attacks, noting that they sometimes operate “in concert” with government forces.