Members of the Free Syrian Army say they have taken hostage seven Iranians, five of whom were allegedly soldiers complicit in the Syrian government's military crackdown on protesters in the opposition-controlled city of Homs.

The Farouk Brigade of the FSA, an umbrella group of members of the country's security forces who defected to protect civilians from the government's attacks, say they will not release the hostages until the government frees a defected army officer and stops the prolonged military siege on Homs.

A video released by the FSA fighters purports to show five of captured Iranians and their identity cards, which allegedly reveal that they are part of Iran's security forces. The defected troops say the other two hostages were civilians.

The video appears to show the hostages admitting to operating as snipers targeting civilians under the direct supervision of Syria's Air Force Security unit.

The Syrian National Council, a leading opposition group, says the development helps confirm many reports from refugees fleeing the country's violence and from activists within Syria, that the Iranian government, a close ally of Damascus, has been logistically backing the 10-month crackdown that has claimed thousands of civilian lives across the country.

But there are concerns over the veracity of the FSA's claims that the five hostages are actually soldiers.

According to a report by Al Jazeera's Nicole Johnston, all the five names of the hostages appear to match the names of five Iranian engineers abducted in December, which were listed by Iranian press.

Furthermore, at least one of the Iranians in the video bear a striking resemblance to a kidnapped engineer.

Haider Ali, one of the hostages, appeared in the video saying:

"I am a member of the revolutionary armed forces of Iran. I am leader of a five-member special team. I entered Syria on Oct. 16, 2011. The others entered Syria on different dates."

"I and my team members, with the support of Syrian security-intelligence forces, were involved in suppressing and shooting ordinary Syrians. We killed a lot of people, including women and children, in the city of Homs."

"We urge Iran's supreme military leader (Ayatollah Ali) Khamenei to order the Iranian military personnel who suppress the Syrians to be repatriated from Syria, so we can also return home," Ali said.

The other hostages also stated their names: Ahmad Aziz Askari, Hasan Hasani, Majid Qanbari, Kyumars Qobadi.

It was not possible to determine if the confession was forced.