Among those kidnapped, who are mostly of members of the minority Druze community, are at least 16 children aged between seven and 15, the human rights group said on Saturday, citing witnesses and relatives.
Local residents told HRW that ISIL (also known as ISIS) is planning to use the hostages as leverage in negotiations with the Syrian government and Russia, one of Syria’s closest allies.
“For a month now, families of the kidnapped Sweida have been calling for the release of their loved ones,” Lama Fakih, HRW’s deputy Middle East director, said in a statement.
“Civilian lives should not be used as bargaining chips, and ISIS should release all the hostages immediately.”
The children were taken during attacks in late July on several villages in the eastern parts of Sweida, HRW said.
Several witnesses told the human rights group that 57 people were killed in the attack, after which 27 were taken by members of ISIL.
Following the attacks, the armed group released videos showing kidnapped women, with one stating that they would be killed if the Syrian government did not stop its assault on Yarmouk, a besieged Palestinian refugee camp held by ISIL in the south of Damascus.
In the weeks following the attacks, local media reported the beheading of 19-year-old Muhannad Abu Ammar at the hands of his ISIL kidnappers.
A woman named Zaya, also taken hostage by ISIL, died of unknown causes several days later.
Sweida province has largely been spared most of the violence that Syrian cities have witnessed in the years since the conflict started in 2011.
In less than a month, Syrian government forces, backed by Russian air power, have been able to seize control of most of southwestern Deraa province, including the provincial capital of the same name.
Alongside the military offensive, the government has also struck “reconciliation” deals, essentially a negotiated capitulation of a number of villages that have been in rebel hands for years, to restore government control there.