The Red Cross statement came as UN observers gathered new details on what happened in a village where dozens were reported killed in a regime assault.
After a second visit to Tremseh today, the team said Syrian troops went door-to-door in the village, checking residents' IDs and then killing some of them and taking others away.
According to the UN, the attack appeared targeted at army defectors and activists. "Pools of blood and brain matter were observed in a number of homes," a UN statement said.
Syria today denied UN claims that government forces had used heavy weapons such as tanks, artillery and helicopters during the attack Thursday in Tremseh.
Syrian Foreign Ministry spokesman Jihad Makdissi said the violence was not a massacre - as activists and many foreign leaders have said - but a military operation targeting armed fighters who had taken control of the village.
"What happened wasn't an attack on civilians," Makdissi told reporters in Damascus. He said 37 gunmen and two civilians were killed - a far lower death toll than the one put forward by anti-regime activists, some of whom estimated the dead at more than 100. "What has been said about the use of heavy weapons is baseless," Makdissi added.
The United Nations has implicated President Bashar Assad's forces in the assault. The head of the UN observer mission said on Friday that monitors stationed near Tremseh saw the army using heavy weaponry and attack helicopters.
The fighting was some of the latest in the uprising against Assad, which activists say has killed more than 17,000 people. Violence continued across the country today, with more clashes reported around the capital, Damascus.