Sudanese President Omar el Bashir (r) holds hands with former leader of the Sudan People's Liberation Army John Garang (July 2005 photo)

Sudanese President Omar al-Bashir has appealed for calm as a third day of violence erupted in the capital, Khartoum, over the death of longtime rebel leader and Vice President John Garang.

In a televised address, President Bashir also announced a joint probe with the southern rebel movement to investigate the helicopter crash that killed Mr. Garang.

Fresh fighting between southern Sudanese, who believe his death was not an accident, and northern Arabs broke out Wednesday as police turned back cars from the center of Khartoum.

The International Committee of the Red Cross says 84 people have been killed in the capital since the violence began on Monday.

Fighting has also been reported in the southern town of Juba.  Witnesses report 18 people dead.

Meanwhile, two U.S. envoys have met with Mr. Garang's successor, Salva Kiir Mayardit, to press for the implementation of January's peace accords ending 21 years of civil war.