Officials in the United Nations' Mission in Sudan said earlier Monday that Sudanese First-Vice President John Garang has been killed in a helicopter crash.
But Xinhua has not got any confirmation from the Sudanese government on Garang's death.
Garang arrived in Uganda on a chartered flight on Friday for a two-day visit, during which he held talks with Ugandan President Yowery Museveni at his ranch in Rwakitura, about 300 km southwest of Ugandan capital Kampala.
Then he left Uganda for home on Saturday on an Ugandan helicopter and the contact with the plane was lost at 6:30 p.m. (1530 GMT) due to bad weather.
The following is the profile of Garang:
Garang was born in a village near the region of Bor on June 23, 1943.
He received a doctorate in economy from the United States' Iowa State University.
In the 1970s, Garang joined the Sudanese army and rose within its ranks to serve as a Colonel.
In 1983, he was sent to squash a rebellion in Bor, but instead established the Sudan People's Liberation Army (SPLA) and turned against the government.
The SPLA won support from Libya, Uganda and Ethiopia, and occupied most areas in south Sudan.
In January 2005, the SPLA signed a peace deal with the government, ending the civil war.
Garang was sworn in as Sudan's first vice president on July 9, as part of the peace deal.
Source: Xinhua