A blast aboard a plane carrying an "official delegation" to Sudan's war-torn South Kordofan state for the Muslim Eid holiday on Sunday killed all 31 on board, an aviation official said.

"All people on board were killed," Abdelhafiz Abdelrahim, spokesman for the Sudan Aviation Authority, told AFP.

He said the plane was landing in Talodi town at about 8:00 am (0500 GMT) when "an explosion was heard and the plane was destroyed."

Abdelrahim could not immediately provide further details.