At least one protester and one police officer were killed and dozens of people injured on Thursday during another day of demonstrations against military rule in Sudan, medics and police said.

Huge crowds have regularly taken to the streets demanding a return to civilian rule since a coup on October 25 coup ended a power-sharing arrangement that began in 2019.

Police said a brigadier-general was fatally stabbed by a protester on Thursday in the capital Khartoum, where security forces fired guns and teargas at demonstrators trying to march on the presidential palace.

In the nearby city of Bahri medics said one protester had been killed by a gunshot to the stomach. Dozens of protesters were being treated for gunshot wounds and other injuries in Khartoum and neighbouring cities, the medics said.

"Crimes are being committed against our revolutionary people," said the Central Committee of Sudanese Doctors, a group aligned with the protest movement.

Asked about the group's statement, police said more than 20 police officers had been injured by the protesters.

Unlike in previous protests, most bridges and roads were left open on Thursday amid a lower security presence in Khartoum after resistance committees rescheduled their protest from Wednesday. Internet and phone services continued to function.

Protesters were seen wearing protective goggles, hard hats, masks and gloves to protect them from teargas. Some pulled up bricks from sidewalks to form barricades, a Reuters witness said.

After they came within a few hundred meters of the presidential palace, the protesters were pushed back as security forces fired heavy tear gas and stun grenades. Injured protesters were carried away by motorcycles, the witness said.

Into the evening security forces fired gunshots at protesters as they retreated to a nearby neighbourhood, witnesses said.

Medics aligned with the protest movement say at least 64 protesters have been killed in Sudan since the coup, mainly as a result of live bullets and teargas from security forces.

Military leaders say their coup has saved Sudan from chaos and say they will protect people's right to peaceful protest.