A close political adviser to Sudan's president has died in a car accident.
Khalifa led the government team at peace talks in Nigeria
Adviser Majzoub al-Khalifa and his brother were killed in the accident in northern Sudan, and several other people were injured.
Khalifa headed the government negotiating team in talks which led to last year's signing of a peace deal with rebels in the Darfur region.
The agreement has failed to halt the four-year Darfur conflict which has made some 2m people homeless.
Chadian President Idriss Deby has cancelled his scheduled visit to Sudan following the announcement of the deaths.
A statement from the president's office read on state television described Khalifa as a "distinguished figure in Sudan".
He served as a minister of agriculture and information under President Omar al-Bashir.
The burial is due to take place on Wednesday.