Sudan army and protesters clash in Khartoum

Elements of Sudan's military have acted to protect protesters in Khartoum after security forces fired tear gas to break up a mass sit-in, eyewitnesses say.

Soldiers tried to chase away pick-up trucks firing tear gas, on the second night of a sit-in protest calling for President Omar al-Bashir to resign.

The eyewitness said the security forces returned for a second attack and people then ran towards a navy facility to seek shelter from the prolonged firing.

Bashir has so far refused demands to make way for a transitional government.

Thousands of people have rallied outside the headquarters of the Sudanese army in Khartoum since Saturday, urging the country's military to back their demands for Bashir's resignation.

Chanting "Sudan is rising, the army is rising," crowds massed on Sunday outside the complex, which also houses Bashir's official residence and the defense ministry.

The protest movement began as a reaction to a government decision to triple the price of bread in December, but it has since escalated into growing demands for Bashir's departure after three decades in office.

Ali Ibrahim, of the Sudanese Professionals Association (SPA), which has organized the protest, told EFE news agency that military units had fired into the air to prevent security forces dispersing the sit-in.

There are unconfirmed reports of casualties from the scene. Video on social media showed protesters hiding behind walls as shots ran out.

The sit-in is taking place outside the army HQ and Agencies quoted witnesses as saying the army has now deployed troops around the building and is erecting barricades in streets near the compound. The army's intentions surrounding the protest remain unclear.

Information Minister Hassan Ismail said the protesters in front of the HQ had been "cleared completely" and the security apparatus was "coherent and working with positive energy and in harmony".