First UN aid reaches Syria's Raqqa since IS defeat

Syria's Raqqa is to receive its first delivery of UN aid since its liberation from the Islamic State group.

The once defacto capital of the militant group, now ravaged by war and littered with unexploded bombs, received a humanitarian mission on Wednesday, the United Nations said.

The head of the UN's Syria humanitarian taskforce Jan Egeland added civilians returning still faced enormous risks.

"Homes are still full of bombs (and) grenades. Children are still being maimed and killed," Egeland said, after receiving a report on the visit, which was carried out in recent days. 

Roughly 100,000 people have returned to Raqqa since IS was ousted in October by fighters backed by a US-led international coalition. 

Egeland said another 100,000 displaced people are waiting near the city and want to go back. 

However the lack of water, electricity and healthcare is compounding the risks of returning.

"It is incredible to have a city with nearly 100,000 people and no public services," the UN official said. "There is no real police (or) law and order."

The battle against IS included a heavy bombardment by coalition jets and left much of the city in tatters. 

Egeland said the extent of the devastation observed by the UN team again raised the question of whether it was "necessary to totally destroy (Raqqa) to liberate it."