A committee in Sudan has begun its work investigating the death of former vice president and rebel leader John Garang.
John Garang helped forge a peace deal after 21 years of war
Mr Garang died two weeks ago, when his helicopter crashed as he was returning from Uganda.
The committee includes aviation experts from both the government and Mr Garang's southern SPLM group.
Both sides have said they believe the crash was an accident, and pledged to stick by a peace agreement that Mr Garang helped forge.
His death sparked days of rioting in the Sudanese capital, Khartoum, and in Juba in the south, in which at least 130 people died.
Some southerners accused the government of having a hand in the crash, and Ugandan President Yoweri Museveni said the cause was not clear.
An international team has also started a separate investigation in Uganda.
The government and SPLM moved quickly to set up the inquiry team, under the chairmanship of a former vice president from southern Sudan, Sayyed Abel Alier, in an effort to calm tensions.
"The committee held its first meeting on Sunday," said Siraj Eddin Hamid, a member of the committee and a former Sudanese ambassador to Uganda.
Mr Garang was succeeded by Salva Kiir, who was swore in as the new vice-president of Sudan this week.
He said he was fully committed to Mr Garang's vision of Sudan as a united country and opposed independence for the south.
Under the peace deal signed in January that ended southern Sudan's 21-year civil war, the south is set to hold a referendum on secession in six years' time.
The civil war pitted the Muslim north against Christians and animists in the south, leaving some 1.5 million people dead.