More than 160 killed as Syrian rebels try to siege

One of those was Ammar Tabajo, who provided information to many Western-based media outlets over the past three years, using the alias Mohammed Saeed.

Abdurrahman and the Local Coordination Committees activist group confirmed Tabajo had been killed.

Tabajo played an instrumental role, particularly in the early phases of the uprising, as a source of information for the media, and was a rare activist who appeared regularly on Arab TV stations.

He was one of the first to report on the Aug. 21 chemical weapons attack, going to makeshift clinics to observe the aftermath.