Chad's government insisted the situation in the capital N'Djamena was stable after shots were fired near the presidential palace.
Foreign Minister Abderaman Kulamalla said in a video apparently recorded at the palace complex that there had been a “small incident” but that “everything is calm”.
Sources close to the African nation's government said there had been clashes between security forces and “terrorist elements”.
French news agency AFP quoted Kulamalla as saying that 18 attackers and a member of the security forces had been killed.
After the incident, tanks were seen in the area and all roads leading to the palace were closed, the agency said
In the video posted on Facebook, Kulamalla is seen surrounded by members of the government forces.
“Nothing serious happened,” he says.
“We are here and we will defend our country with our blood. Be calm.
This whole attempt at destabilization was foiled.
He is then seen taking pictures with the soldiers and raising his fist with them.
Kulamala, quoted by AFP, said the attack was carried out by a 24-member commando squad, adding that six of the attackers suffered injuries.
Three other members of government forces were also injured, he added.
The incident came just hours after a visit to the former French territory by Chinese Foreign Minister Wang Yi, who met with President Mahamat Deby and other senior officials.