N'DJAMENA, Jan 8 (Reuters) - Chad's government said on Tuesday its armed forces were ready to carry out further bombing raids over the border in Sudan's Darfur region on Chadian rebels.

The United Nations said on Monday that Chadian planes had bombed rebel positions near el Geneina, the capital of Sudan's western Darfur state, on Sunday, adding to tensions between the two countries.

"If that's the case, it means there were rebels in those localities which were bombed," Chad's Communication Minister Hourmadji Moussa Doumgor told French radio RFI when asked about the reported strikes on the villages of Goker and Wadi Radi.

Asked if there would be further air strikes, he said: "We will continue as long as there is a threat of attack coming from Sudan."

Relations between Chad and Sudan have been tense in recent years as both try to quell insurgencies close to their long and porous border. They accuse each other of backing rebels trying to overthrow their respective governments.

"Chad does not want an escalation. Chad does not want war with Sudan ... But Chad is taking the necessary measures to ensure the security of its border," Doumgor said.

Rodolphe Adada, head of the African Union-United Nations force for Darfur, said on Monday the border tensions could negatively affect the planned expansion of the joint peacekeeping mission.

Sunday's reported strikes came a day after Chadian President Idriss Deby threatened to send his armed forces into Sudan to destroy rebel fighters he accuses Khartoum of supporting.

Aid workers speaking on condition of anonymity confirmed there had been air attacks in the area.

Sudan has repeatedly denied supporting Chadian rebels and warned Chad not to take military action. The Sudanese army has said it is ready to repel any attack on its territory. (Writing by Nick Tattersall; Editing by Daniel Flynn and Keith Weir)