BEIRUT: A sniper killed an Al-Jazeera reporter in southern Syria on Friday, the pan-Arab television network said, in the second such shooting of a journalist in two days in the conflict-swept country.

The killings take the death toll of reporters who have died in Syria's 22-month conflict to at least 20, according to a count by AFP and Paris-based media watchdog Reporters Without Borders, or RSF.

"Mohammed Hourani was shot dead by a regime sniper in Basra al-Harir in the province of Daraa, while he was covering the clashes there," Al-Jazeera said in a statement.

The Qatar-based satellite news channel confirmed Hourani's killing, and described the 33-year-old Syrian journalist as "courageous and accurate" in his reporting.

Before joining Al-Jazeera, Hourani was an activist in the uprising against President Bashar al-Assad, the broadcaster said.

Outspoken in its support for the revolt against the Assad regime, Al-Jazeera vowed to pursue its editorial line despite the latest killing.

Amateur video posted online and distributed by activists showed the moment that Hourani was killed.

Wearing a beige jumper and carrying a microphone embossed with Al-Jazeera's logo, he stood in a line of rebel fighters running one by one across a muddy alley, ducking as they sped to avoid being shot by snipers positioned nearby.

Hourani was hit as a sniper fired at least three shots, and fell to the ground.

He was the second reporter to be killed by snipers in 24 hours in strife-torn Syria.

On Thursday, Belgian-born French journalist Yves Debay was shot dead in the northern city of Aleppo, said the Syrian Observatory for Human Rights.

"He was killed on one of Aleppo's fronts," said the Aleppo Media Centre, adding he was "shot by a regime sniper".

The AMC's Abu Hisham told AFP via the Internet that he was first alerted of Debay's killing by a volunteer at an Aleppo field hospital.

Another activist who spoke to AFP via the Internet on condition of anonymity said he helped put Debay's body in an ambulance en route to the Bab al-Salama border crossing with Turkey.

"It is not exactly clear how he was killed, but it seems like he entered a very dangerous street where the army and pro-regime militia were positioned," he said.

Debay founded Assaut magazine, a French publication specialised in defence.

"Reporters Without Borders is very disturbed by the way journalists are being caught in the spiralling violence," RSF said on Friday.

"We condemn the growing threats to journalists, who are often being targeted," the head of the media watchdog, Christophe Deloire, said in a statement.

"Syria is now the world’s most dangerous country for news providers of all kinds," he said.