Villagers say they have found 13 bodies buried on farmland near Deraa - but government says claim is "totally false".
"....Deraa residents say hundreds of people have been missing since tanks and soldiers moved in last month to crush opposition to President Bashar al-Assad's 11-year rule.
They said villagers digging in farmland in the outskirts of the city uncovered the decomposed bodies of Abdullah Abdul Aziz Aba Zaid, 62, and four of his children.
The villagers also found the bodies of a woman, a child and six men, all unidentified, residents said on Monday.
It was not clear when they died, but Deraa residents said dozens of civilians were killed during the military assault on the city's old quarter.
"[The residents] discovered a mass grave in the old part of town but authorities immediately cordoned off the area to prevent residents from recovering the bodies, some of which they promised would be handed over later," a rights activist told the AFP news agency by phone on Monday.
Accounts of the mass grave could not be independently verified as Syrian authorities have all but sealed off the country to foreign journalists.
Syrian and international rights groups say Syrian forces have killed at least 700 civilians, including women and children, across the country since the protests broke out in Deraa on March 18.
In another development in Deraa and in other cities across Syria, thousands of protesters have begun demonstrating at night in order to avoid tough security measures that are in force during the day.
On Monday night, thousands of demonstrators marched through the Damascus suburb of Saqba at the funeral of Ahmad Ataya, who died of wounds inflicted when security forces fired at a pro-democracy rally in the capital last month.
It was the biggest protest in the Damascus outskirts since a security crackdown three weeks ago......"