Chad, Africa's newest oil producer, has accused neighbour Sudan of seriously threatening its security. The allegations made on Friday were likely to sour bilateral relations, already weakened by a vicious war in Sudan's Darfur region, which borders eastern Chad. Chad's Defence Minister Emmanuel Nadingar said there is "a build up of politico-military forces in the El-Geneina zone. It's not a secret. Three thousand Chadians are organised, prepared and heavily kitted out by the Sudanese government to destabilise Chad." He added that security measures had been taken to protect Chadians while waiting for clarifications from Khartoum. El-Geneina is the capital of the West Darfur state near the border with Chad, an arid landlocked state twice the size of former colonial ruler France. The Darfur crisis has created political and economic problems for Chad, with the government coming under pressure from both sides of the conflict for support. Chad has also accused Sudanese militias of launching cross-border attacks.