(Xinhua) -- Chadian President Idriss Deby Itno appointed a close ally Mahamat Ali Abdallah Nassour as defense minister on Friday amid a state of emergency in this central African country. According to reports from N'Djamena, Chad's capital, soldiers and police tightened security and searched from house to house for rebels across the country. The new defense minister, Abdallah, previously the mining minister, had acted as head of government while Deby hid from the rebels storming the capital. Deby declared on Thursday a nationwide state of emergency after a rebel attack on N'Djamena. Allied rebels, with some 3,000 fighters, staged an offensive in the capital in a bid to overthrow the government of Deby from Feb.2 to Feb 3. After violent fighting, they gave up the aborted attempt and withdrew to the central part of the country before starting their southward movement.