The British Broadcasting Corporation (BBC) said that 13 people were killed in the bombing of a hospital in a besieged Sudanese city.

At least 13 people were killed after an attack on one of the last remaining hospitals in the besieged Sudanese city of El Fasher.

A source told the BBC that 16 others, including a doctor and a nurse, were injured after the paramilitary Rapid Support Forces bombed a Saudi hospital several times on Tuesday evening. A group of Sudanese doctors described the attack as a war crime.

Pictures showed shattered windows, cracks of shrapnel, a hole in the mud-brick wall and twisted metal parts of hospital beds covering the floor.

The Rapid Support Forces have besieged the city of El Fasher for more than 17 months, leaving hundreds of thousands of people stranded in the city, facing starvation.

This paramilitary group is fighting the army for full control of El Fasher, the last military stronghold in the vast Darfur region.

This is the second raid on the Saudi hospital this year, as the first raid in January resulted in the death of three children and the injury of three others.

The recent bombing destroyed part of the hospital and destroyed wings.

In recent weeks, the Rapid Support Forces have intensified their attack on El Fasher, leading experts to believe that the city may fall soon unless the army receives immediate reinforcements.

The two sides have been waging a fierce civil war for more than two years, causing the world’s worst humanitarian crisis and tens of thousands of deaths.

Research showed on Tuesday that the Rapid Support Forces had finished building a dirt wall around the city of El Fasher, strengthening their siege and making it difficult for civilians to escape.

The Rapid Support Forces began building the berm in May, satellite images analyzed by Yale University’s Human Research Laboratory found.

All major exit routes by the 57-kilometre (35-mile) wall are now closed, and civilians trying to flee have reported extortion, arbitrary arrest, disappearances and sexual violence at checkpoints controlled by the RSF.

The ongoing fighting in El Fasher has led to the closure of most health facilities. Aid convoys carrying food and health care were prevented from reaching civilians.

UN High Commissioner for Human Rights Volker Türk said last Thursday: “After more than 500 days of continuous siege by the Rapid Support Forces and continuous fighting, El Fasher is on the brink of an even greater catastrophe if urgent measures are not taken to ease the armed tension in the city and protect civilians.”