Two children were killed and five injured in northwest Syria because of violence that occurred in the first four days of the new year, UNICEF said Tuesday.

"Last year, more than 70 per cent of grave violations against children in Syria were recorded in the northwest," the international organization said in a statement.

"Children and services catering to them must never come under attack," it said. "It has been 11 brutal years of war on the children of Syria. How much longer can this go on?"

The agency said earlier this week that a UNICEF-supported water station came under attack in the Arshani village outside Idlib in northwestern Syria.

"The attack put the station out of service cutting water supply for over 241,000 people, many of whom are internally displaced," it added.

Syria has been ravaged by a civil war since early 2011 when the Bashar al-Assad regime cracked down on pro-democracy protesters.

Hundreds of thousands of people have been killed and more than 10 million displaced, according to UN estimates./aa