AFP stringer Mazhar Tayyara was killed last night in the besieged Syrian city of Homs – which has been under Syrian army shelling for days – according to news reports.

Tayyara, 23 or 24 years old according to different reports, provided video footage and information to AFP, the Guardian, Die Welt and had appeared on CNN and Al-Jazeera television news networks, AFP reported. He was reportedly known by the nicknames “Omar the Syrian” and “Omar Astalavistas,” according to AFP and die Tageszeitung, respectively.

The circumstances of Tayyara’s death vary in different reports. AFP quoted activists who said he died while helping people who were wounded in the shelling of Khaldiyeh neighbourhood. A report on the website of die Tageszeitung quoted others who said that Tayyara was killed when his home was hit by shelling, and cite yet another account that said Tayyara was hit while reporting.

Foreign journalists are banned from travelling to Syria and local journalists cannot work openly, making it difficult for international news media to confirm information received from citizen journalists and activists.

“The tragic killing of Mazhar Tayyara highlights the perils faced by those in Syria who seek to transmit – at the risk of arrest, torture and death – independent information,” said IPI Press Freedom Manager Anthony Mills. “If it were not for the courage of stringers and other journalists, including citizen reporters, the world would not be bearing witness to the grave abuses currently being committed in Syria.”

Tayyara is the fourth journalist to have been killed in Syria since the start of the anti-government uprising, according to IPI’s Death Watch. Shukri Abu el-Burghol, a journalist formerly with a Syrian state-run newspaper, was shot on January 2. Gilles Jacquier, a correspondent for France 2 television, was killed in a grenade explosion while covering demonstrations in Homs on January 11. Last November, cameraman Ferzat Jarban was found with his eyes gouged out after filming protests in the town of al-Qasir, in Homs province.