At least four people were killed and 30 injured in shootings by revelers celebrating the New Year in several regime-held areas of war-ravaged Syria, medical sources said on Monday.

The dead included two in the central province of Hama, a third in the northern city of Aleppo and a child in the coastal city of Latakia, the sources told dpa.

An official at the Syrian Interior Ministry criticized the tradition of celebratory shootings in the country wracked by a civil war in its seventh year.

"There are several regulations banning this," the official said.

"But some people ignore this ban as though Syrians, who are being killed in battles, just need to be shot dead in their celebrations," he added on condition of anonymity.

Syria's crisis began with peaceful anti-regime demonstrations in March 2011.

The conflict soon spiraled into a multi-sided civil war that has claimed hundreds of thousands of lives and displaced about half of Syria's pre-war population of 22 million.

More than 494,000 people are estimated to have been killed in the conflict, the Syrian Observatory for Human Rights, a war monitor, reported this week.