At least 13 Sudanese protesters killed as security forces attack Khartoum sit-in

Sudanese security forces have used live ammunition in a major operation to disperse protesters from a central Khartoum sit-in, killing at least 13 and injuring dozens more, according to a medical association.

The news of the crackdown sparked sporadic unrest around Khartoum. Thousands of protesters were reported to have blocked roads with stones and burning tyres in Omdurman, the twin city neighbouring the Sudanese capital. Other estimates put the death toll at 10.

Smoke was seen rising from several locations in Khartoum and at least one bridge across the Nile was reported to have been blocked by burning tyres.

The sit-in has been the centre of a campaign to bring democratic reform to Sudan, which has been ruled by a military committee since the fall of the dictator Omar al-Bashir in April.

Witnesses reported that security forces belonging to the feared Rapid Support Forces (RSF) had surrounded and entered hospitals, firing weapons, beating medical staff and injuring protesters.

"The protesters holding a sit-in in front of the army general command are facing a massacre in a treacherous attempt to disperse the protest," said the Sudanese Professionals Association (SPA), the group that spearheaded nationwide protests that started in December.

Live images broadcast by Arab television stations showed tents used by the protesters on fire, as other demonstrators ran away from the scene. There were reports of heavy and sustained gunfire at the protest site, which is in front of the defence ministry, and elsewhere in Khartoum.

A witness living in the Burri neighbourhood in east Khartoum said he could "hear the sound of gunfire and I see a plume of smoke rising from the area of the sit-in".

There were also reports of security forces breaking up demonstrations elsewhere in Sudan, though it was unclear if there had been casualties.

Foreign journalists in Khartoum said they were being confined to a hotel by unidentified security personnel.

The SPA said the attacks were a "bloody massacre" and called on Sudanese people to take part in "total civil disobedience" to topple the military council and for people for take to the streets to protest.

The Sudanese Air Pilots Association was reported to have decided to support the call, which could severely affect flights to Khartoum. Other professional bodies also said they would strike in protest at the new violence.

The Sudanese military ousted Bashir in April after months of protests against his 30 years in office. Thousands of protesters camped outside the ministry, first demanding that military rulers oust Bashir and then that they hand over power to civilians.

Though consensus on the broad outlines of a deal to install a civilian government has been reached, protracted negotiations between a coalition of pro-reform groups and the military have foundered on the question of who would dominate the top decision-making body during an interim period.

Monday's operation appeared to be conducted by the paramilitary RSF, which have been accused of systematic human rights abuses. They are led by Mohamed Hamdan Dagalo, known as Hemedti, who also serves as deputy head of the transitional military council, the country's governing committee.

By mid-morning there were reports that RSF units had taken up positions throughout the Khartoum.

It is unclear if the regular military had backed the crackdown, raising the prospect of a dangerous split within security forces.

Shams al-Deen al-Kabashi, a spokesman for the ruling council, said in televised remarks that the military had targeted an area near the sit-in but that the violence had spilled over into the main site.

Kabashi did not say whether the military wanted to break up the sit-in, and other media reported that he had said the ruling council wanted to continue negotiations with the protesters.

Experts have previously warned of a "nightmare scenario" in which infighting among militia and soldiers leads to a complete collapse of the state.

Irfan Siddiq, the British ambassador in Sudan, said he was extremely concerned by the heavy gunfire he had heard from his official home in Khartoum and the reports that Sudanese security forces were attacking the protest sit-in site. "[There is] no excuse for any such attack," he said on Twitter.

The military rulers of Sudan were responsible for the crackdown, the US embassy in Khartoum said. "Sudanese security forces' attacks against protesters and other civilians are wrong and must stop," it said.