The bodies were found Friday night in a cemetery on the southern edge of a city, the Los Angeles Times reported. Many of the bodies showed signs of torture, said activist Muhammad Younis.
Government security forces went door-to-door in the city and executed people in the streets about three weeks ago, Younis said.
"There were young children who were burned, the bodies were disfigured," he said. "He committed massacres so he would create chaos and fear."
The discovery came as U.N.-Arab League envoy to Syria Lakhdar Brahimi arrived in Damascus for talks with government forces and rebels on a cease-fire, officials said. Details of the talks between Brahimi and Foreign Minister Walid Muallem have not been released, Voice of America reported.
Brahimi is scheduled to meet with President Bashar Assad as well as rebels while in Syria.
Brahimi wants Syria to take part in a four-day cease-fire during the Islamic Eid al-Adha holiday that begins Friday, the report said.
The envoy arrived in Damascus to the sounds of shelling in the city's suburbs, the BBC reported.
Fighting also was reported in Harem on the border with Turkey.
At least 30,000 people are reported to have been killed in fighting that began about 18 months ago.
A cease-fire in April fell apart after just a few days.