At least 43 civilians were killed on Saturday by a fresh round of US-led airstrikes on the northern city of Raqqa, state news agency SANA reported.

SANA said the victims lost their lives when the US-led warplanes carried out several air raids, targeting residential areas in Raqqa, Xinhua reported.

This comes hours after seven children were killed in Raqqa on Friday.

SANA said the US coalition went on a spree of airstrikes targeting the residential areas in the city.

Meanwhile, Dina Asa'ad, a Raqqa-based official in the Syrian Arab Red Crescent (SARC), said the coalition carried out an attack on Thursday evening on Raqqa with white phosphorous.

In remarks carried by SANA, Asa'ad said the white phosphorous bombs struck the National Hospital in Raqqa.

"Over 20 bombs struck the hospital, which damaged the electricity generators, ambulances and several wards inside the hospital," she was quoted as saying.

The hospital serves over 100,000 people in the city, she noted.

Asa'ad pointed out that there is no presence of the IS militants in the hospital, adding that what Raqqa is subject to cannot be fighting terrorism, but destruction.

"The attacks targeted schools and bakeries. Even the government institutions have been completely destroyed as well as the water wells in the city," she said.

Fawaz Assaf, the head of SARC in Raqqa, said the US-led coalition and the Kurdish-led Syrian Democratic Forces (SDF), which are jointly fighting IS in Raqqa, are implementing the "scorched land" tactic.

Over 65 governmental institutions and buildings have been completely obliterated, he said, adding that the sugar factory is the most important of those destroyed establishments.

He added that the shelling and airstrikes hit the schools, banks, marketplaces, and bakeries, noting that the streets have become empty of buyers.

Two months ago, the SDF, with help of the US, unleashed a wide-scale offensive to drive out IS from Raqqa, seizing control of 45 per cent of the city.

But the Syrian government has countlessly complained to the UN Security Council about what it described as "the crimes of the coalition" in targeting civilians and destroying infrastructure.

The Syria Foreign Ministry has urged the UN to dissolve the US-led coalition, which started its operations in Syria in 2014.