The leader of an attempted coup on Sunday in the Democratic Republic of Congo (DRC) has been killed and some 50 people including three American citizens arrested, a spokesman for the Central African country's army told Reuters.

Gunfire rang out around 4 a.m. in the capital Kinshasa, a Reuters reporter said. Armed men attacked the presidency in the city centre, according to spokesman Sylvain Ekenge.

Another attack took place at the nearby home of Vital Kamerhe, a member of parliament who is tipped to become speaker, Kamerhe's spokesman, Michel Moto Muhima, and the Japanese ambassador said in posts on X.

Moto Muhima said two guards and an attacker had been killed in that incident. Ekenge also said one attacker was killed there.

A shell fired from Kinshasa hit the city of Brazzaville in neighbouring Republic of Congo, injuring several people, that country's government said in a statement, adding that one person had been hospitalised.

Ekenge named Christian Malanga, a U.S.-based Congolese politician, as the leader of the attempted coup.

"Malanga was definitively neutralised during the attack on the Palais de la Nation, a certain Aboubacar was neutralised during the attack on the residence of Vital Kamarhe [and] the others - around 50 including three American citizens - were arrested and are currently undergoing interrogation by the specialised services of the Armed Forces," Ekenge told Reuters.