A global activist group says nearly 3,000 people have "disappeared" in Syria since March during the government's crackdown on a political uprising.
The Avaaz organization announced its findings on Thursday as it launched a campaign to pressure Syria to allow an international delegation to investigate the disappearances.
Meanwhile, The Associated Press quotes Syrian activists who say security forces swept through a Damascus neighborhood on Thursday and arrested more than 100 people.
Syria's military has been carrying out raids across the country as part of the government's ongoing crackdown on dissent.
Activists say at least 11 people were killed Wednesday during a security sweep in the town of Kanaker near Damascus. They say troops arrested at least 250 people.
In spite of the crackdown, anti-government demonstrators rally almost daily for the resignation of President Bashar al-Assad.
Rights groups say Syrian forces have killed at least 1,600 civilians during the past four months in the crackdown on dissent.
Some information for this report was provided by AP.