Chad’s army says it killed at least 300 rebel fighters who attacked the northern part of the country eight days ago, adding that it lost five soldiers in the incursion, which it said was repulsed.
There has been no independent confirmation of the army’s statement.
The heavily armed rebels – opposed to President Idris Deby’s rule – launched the raid from their base in neighbouring Libya on 11 April, the day Chad held its presidential election.
On Saturday, the US embassy in the capital N’Djamena ordered its non-essential staff to leave the country, citing “the possibility of violence in the city”.
The UK has also recommended that its nationals leave the country “as soon as possible”.
However, Chadian Foreign Minister Amine Abba Sidick called on diplomatic missions for calm, saying the situation was under control.
Opposition and civil society groups have asked President Deby to organise national dialogue to ease tension.
Mr Deby has ruled the country since 1990 and is expected to secure a sixth term.