THE Rapid Support Force (RSF), a paramilitary group that has been at war with the Sudanese military for over two years, said today it has agreed to a humanitarian truce proposed by a US-led mediator group.

The RSF’s agreement to the proposal comes over a week after the group seized el-Fasher city, which had been under siege for over 18 months. It was also the last Sudanese military stronghold in the Sudan’s western Darfur region.

But a Sudan military official said the army will only agree to a truce which includes withdrawing from civilian areas and giving up weapons.

Satellite images revealed today what appear to be mass burials being conducted in el-Fasher.

Analysis of the images, by the Yale School of Public Health’s Humanitarian Research Laboratory of images produced by United States imaging firm Vantor, raise further concerns about the scale of the violence that has hit the city as the two-year war grinds on in Sudan.

The images appear to reveal mass graves being dug and later covered at two sites in the city, one at a mosque just north of the Saudi hospital where some 460 people reportedly had been killed and another by a former children’s hospital that the RSF had been using as a prison, the Yale researchers said.

Their report said: “It is not possible based on the dimensions of a potential mass grave to indicate the number of bodies that may be interred. This is because those conducting body disposal often layer bodies on top of each other.”

The RSF denies the accusations.

UN secretary-general Antonio Guterres has called for “mechanisms of accountability” over the el-Fasher seizure “because the crimes that are being committed are so horrendous.”

The RSF is also accused of kidnapping thousands of local people in el-Fasher and forcing families to pay ransoms for their release.

When the RSF stormed el-Fasher on October 26, resident Mabrooka’s husband and brother ran for their lives but she later received a phone call from an RSF fighter demanding that 14,000 Sudanese pounds (£17) be wired to a bank account.

She told Al Jazeera: “I knew they would for sure torture and kill them if I didn’t muster up the money.”

Al Jazeera is reporting that ransoms range from anywhere from £15 to £15,000.

Mathilde Vu, the Sudan advocacy manager for the Norwegian Refugee Council, said many civilians are reportedly being detained as they flee and asked to pay a “transportation fee.”