A group of Libya-based rebels attacked a Chadian border post in the north of the country as polling stations began counting votes from the weekend presidential election, the Chad government said late on Monday.
President Idriss Deby, an ally of western powers in the fight against Islamist militants in West and Central Africa, sought to extend his 30-year-rule over the central African country in an election boycotted by several opposition groups.
Results have not yet been announced.
A group of heavily armed vehicles crossed the border from Libya and attacked the border post at Zouarké at around 6 p.m. (1700 GMT) on Sunday, government spokesman Chérif Mahamat Zene said in a statement.