Four journalists have died this week covering the conflict in Syria: three from the Syrian opposition television channel Orient News, and one working for Al Jazeera's online platform

Orient News correspondents Rami Asmi and Yousef El-Dous, and cameraman Salem Khalil, were killed on 8 December 2014 when a missile hit their vehicle near Al Sheikh Maskin in Deraa province, said the Committee to Protect Journalists (CPJ).

Two days later Al Jazeera's Mahran Al Deeri was killed, also while covering battles between Syrian government forces and insurgents in his home-town of Al Sheikh Maskin. Al Deeri, 31, studied at Damascus University and worked for the Syrian Government news agency SANA until the beginning of the conflict when he became an independent journalist.

"Our martyred colleague Mahran Al Deeri has worked with for over a year and was known for his courage, bravery and professional coverage of the Syrian revolution in the area of Daraa and its suburbs," said Mostefa Souag, acting director general, Al Jazeera.

"It's left to local journalists to bring the world news of the fighting in Syria, but they are paying a terrible price," said CPJ Deputy Director Robert Mahoney. "Mahran al-Deeri is the fourth media fatality there in less than a week."

At least 75 journalists have been killed while covering the war in Syria, which is now in its fourth year, says the CPJ.

"Targeting journalists will not deter us from reporting the truth which we have been committed to for over 18 years", added Al Jazeera's Souag.

Read more: Journalist death toll rises in Syria with Al Jazeera, Orient TV killings | News | Rapid TV News