The Red Cross statement on Sunday came as United Nations observers gathered new details on what happened in a village in Tremseh. They said Syrian troops went door to door, apparently looking for army defectors and activists. Dozens of people were reportedly killed.
Syria denies the claim, saying last Thursday's raid was a military operation targeting armed fighters who had taken control of the village.
The fighting was some of the latest in the uprising against President Bashar Assad, which began more than a year ago. Activists say more than 17,000 people have been killed.
Violence continued Sunday, with more clashes reported around the capital.
The Associated Press contributed to this report.