Capturing ruthless killings on camera. Going to conflict zones to film gun battles between the Islamic State (ISIS) militants and their adversaries.

These are only some of the risky and brutal jobs performed by members of the ISIS propaganda team, as revealed by detained defectors of the extremist group to The Washington Post.

Abu Hajer al-Maghribi, who spent nearly a year as a cameraman for ISIS, for instance, recalled how he received his assignment card one day, and ended up being a witness to the massacre of more than 160 Syrian soldiers in 2014.

Abu Hajer, a soft-spoken man in his mid-30s now jailed in Morocco for his ties with the ISIS, was told by his assignment slip bearing the ISIS flag to travel two hours southwest of the Syrian city of Raqqa, the capital of the caliphate.

"The paper just gives you the location," Abu Hajer told The Washington Post.

He recounted how he filmed the Syrian soldiers who were forced to walk through the desert with only their underwear on, and then shot dead while on their knees.

"I held my Canon camera," he recalled. The horrific video shot by Abu Hajer went viral online, and was even picked up by news organisations like Al Jazeera.

Abu Abdullah al-Maghribi, a second defector who was part both of the ISIS security and propaganda ranks, meanwhile shared how extensive the ISIS media arm was.

"It is a whole army of media personnel," Abu Abdullah also told The Washington Post.

He also said members of the ISIS propaganda team hold a higher place in the extremist organisation. Senior media operatives are even treated as "emirs," which are of equal rank to their military counterparts.

"The media people are more important than the soldiers," he said. "Their monthly income is higher. They have better cars. They have the power to encourage those inside to fight and the power to bring more recruits to the Islamic State."