Al-Nimir, and two of his colleagues, Issam Obeid and Abdel Karim Nazir Ismail, were killed when a mortar shell hit them while they were filming clashes between security forces and armed rebels in the southern Damascus suburb of Arbin, according to news reports.
The rebel Free Syrian Army captured Arbin in July 2012, but has been engaged in continuous battle with Syrian government forces over the suburb, according to news reports.
The three videographers contributed to the Syrian Media Center, a local news organization that has posted thousands of videos and news stories documenting the Syrian conflict since March 2011.
The Syrian Media Center posts news and reports from around the country covering the conflict, politics, clashes, and protests and is picked up by several regional news outlets including Al-Jazeera. The center does not publish footage under individual bylines.
With an effective ban on foreign journalists and with local media neutralized, international media relied heavily on reporting and footage shot by al-Nimir and other citizen journalists.