More than 400 people have been killed in recent attacks by the paramilitary Rapid Support Forces (RSF) in Sudan's Darfur region, says the UN, citing "credible sources".

Last week, the RSF launched an intense ground and aerial assault on refugee camps surrounding the city of El-Fasher in an attempt to seize the last state capital in Darfur held by their rival, the Sudanese army.

The two warring sides have been locked in a bloody power struggle since April 2023. This has created the world's largest humanitarian crisis and forced millions to flee their homes.

The UN said it had verified 148 killings between Thursday and Saturday, but warned the toll was much higher.

UN spokeswoman Ravina Shamdasani told the BBC their verification process was still ongoing and their number didn't include Sunday's violence.

"Credible sources have reported more than 400 killed," said Ms Shamdasani.

At least nine humanitarian aid workers were among those killed, the UN said.

The refugee camps that surround El-Fasher - Zamzam and Abu Shouk - provide temporary homes to more than 700,000 people, many of whom are facing famine-like conditions.

In a statement released on Saturday, the RSF said it was not responsible for attacks on civilians and that scenes of killing in Zamzam were staged to discredit its forces.

The following day, the group said it had completed a "successful liberation" of the camp from Sudan's army. The RSF accused the army of using Zamzam as "a military barracks, and innocent civilians as human shields".

El-Fasher is the last major town in Darfur under army control and has been under siege by the RSF for a year. Sudan's brutal civil war will enter its third year on Tuesday.

UN Human Rights Chief Volker Türk called on all parties involved to "renew their resolve to take meaningful steps towards resolving the conflict".

Ahead of a conference on Tuesday in London to mark the conflict's two-year anniversary, UK Foreign Secretary David Lammy announced a £120m food and aid package for Sudan.

He said Sudan's stability is "vital for our national security".

The UK will co-host the talks alongside the African Union and European Union.