BEIRUT - At least 28,000 Syrians have gone missing since they were abducted by forces loyal to President Bashar Assad during the 19-month-old revolt, activist group Avaaz said on Thursday.

Quoting statements from Syrian human rights lawyers and families, Avaaz said security forces had set out to terrorize communities by grabbing people off the street and torturing them.

Other rights groups have also accused Syrian rebel groups of abducting people they deem pro-government.

One Syrian-based human rights organization reported up to 80,000 people had disappeared, added Avaaz, a campaign network that aids opposition activists in Syria alongside other causes worldwide.

The figures could not be verified independently.

Activists say 30,000 people have been killed in Syria's conflict which started with peaceful protests but turned violent after months of oppression.

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