"This was a group known as the Shabiha. This is a government militia. These are people who are loyal to President Bashar Assad," Engel said on air Tuesday morning.
An NBC news team, including chief foreign correspondent Richard Engel, was freed in Syria Monday after an Islamist rebel group killed two of their kidnappers at a checkpoint, the network reported on its website Tuesday.
The team, which later spoke live on the network, were held captive by an unidentified group for five days.
Engel, 39, and two other members of the news team, disappeared shortly after crossing into northwestern Syria from Turkey on Thursday. The network had not been able to contact them until they were freed.
"It was a very traumatic experience," Engel said on NBC's "Today" program.
Engel, speaking from Antakya, Turkey, said they were not physically beaten but there was psychological torture, including threats of being killed and mock shootings.
The network said the team was bound and blindfolded but not harmed. There was no claim of responsibility and no request for ransom, NBC said.