Numerous corpses, including those of children, have been found in the Syrian city of Homs, activists and state media have said. Activists are urging the UN Security Council to hold an emergency meeting over the matter.
Differing accounts put the number of dead found in Homs between 12 and 50 on Monday.
"Most of the bodies had traces of torture, some were burnt alive and others were slaughtered with knives," activist Omar Homsi told the AFP news agency.
Some of the bodies had their throats cut, activists said.
"We call on the United Nations to hold an emergency meeting immediately. This is a massacre which is documented with all names and identities," Walid al-Buni, a member of the Syrian National Council, told the DPA news agency from Istanbul.
"The world community cannot stay silent anymore," al-Buni said.
The forces of Syrian President Bashar al-Assad have been trying to crush a popular uprising in the country for the past year. The UN says more than 7,500 people have been killed in the fighting.
ncy/slk (dpa, AFP, AP)