The Syrian opposition appealed Thursday for emergency fuel deliveries to rebel-held areas, saying two children had "died of cold" as a winter storm gripped the region.

The opposition National Coalition said that parents were unable to keep children warm in bombed out buildings as temperatures plummeted and snow carpeted many of Syria's main battlegrounds.

"Hussein Tawil, a six-month-old baby, died of cold yesterday (Wednesday) in Aleppo," Syria's second city which has been a key battleground since July last year, Coalition spokesman Soner Ahmad told AFP.

"He was probably living in a house that had been damaged," Ahmad said.

Another child died from the cold in Rastan, a rebel-held town in the central province of Homs, he added.

Video footage posted online by activists showed the lifeless body of a small child that the unidentified cameraman said had died of cold in Rastan. AFP could not verify its authenticity.

"The situation is terrible. There is no fuel," Ahmad said, appealing for urgent help for Syrians inside the country and in refugee camps abroad to cope with the wintry conditions.

The education ministry ordered those schools still operating in government-held areas to close because of the extreme weather.

Drifting snow blocked several roads in Homs province, the state SANA news agency said.

A photograph of bombed out buildings in the province covered in snow went viral on the Internet.

A Syrian activist, who works with aid agencies on the Turkish border, told AFP by Internet that the snow and ice were making it more difficult for them to get supplies into rebel-held areas of the north.

"The situation is very difficult," said the activist, who gave his name only as Ammar.

"In some areas, people cannot afford fuel for heating, so they are chopping down trees.

"In other areas, there isn't any fuel at all... And the poor conditions on roads are making it more difficult to take in humanitarian assistance."

Ammar said that in the eastern city of Deir Ezzor, hub of Syria's oil industry before the civil war and Western sanctions decimated production, people were burning unrefined crude to keep warm.

"This is very, very harmful," he warned.