Rebels in Sudan's main oil state said on Thursday they had shot down a government Antonov military aircraft after it had bombed targets in the Nuba mountains, part of South Kordofan state.Sudan's armed forces spokesman did not immediately respond to requests for comment.Insurgents of the Sudan People's Liberation Movement North (SPLM-N) said in an emailed statement they had downed the aircraft around 5 p.m. (1400 GMT) on Wednesday in South Kordofan's Jau area, near the border with South Sudan.It was not immediately possible to verify the claim. Sudan restricts access for journalists to South Kordofan, where fighting between rebels and government forces broke out shortly before South Sudan seceded last year."Before it was downed, it (the Antonov) carried out air strikes on various areas in the Nuba mountains," the SPLM-N statement said, referring to an area in South Kordofan.Rebels in South Kordofan fought alongside southern insurgents during Sudan's civil war but were left in Sudan when South Sudan seceded under the 2005 peace deal that ended that long-running conflict.They say they are fighting to protect their ethnic minority from persecution. Khartoum accuses them of trying to sow chaos at South Sudan's behest.