Congolese security forces repelled an attack by about 20 gunmen at the main military barracks in the capital, Kinshasa, and deployed tanks to secure the installation, government spokesman Lambert Mende said.

At least seven attackers and one soldier died in the assault on Camp Tshatshi yesterday afternoon, Mende said by phone today from the city. The raid forced some offices to close as employees went home, though by today business had returned as normal, he said.

While the city’s N’djili Airport was evacuated and secured by the military, it wasn’t closed down, Mende said. The central bank’s weekly Treasury-bill auction was canceled because of the attack.

The Democratic Republic of Congo is the world’s sixth-largest producer of copper and the biggest of cobalt. The central African nation, which is about the size of Western Europe, has been ruled by President Joseph Kabila since he took office 10 days after his father, Laurent Kabila, died in January 2001. The country is scheduled to hold presidential elections in 2016 and opposition parties have said Kabila may change the constitution to secure a third term, which is currently illegal.

Even if the attack on the barracks was a one-time incident, it may damage Kabila’s image, said Stephanie Wolters, head of the conflict prevention and risk analysis program at the Institute for Security Studies in Pretoria.

On Dec. 30, at least three soldiers and 52 assailants died in another attack on Camp Tshatshi.

“It does not look good that people are willing to risk their lives to attack the government, especially given the ongoing controversy about whether or not Kabila is going for a third term,” said Wolters. “An attack like this sends a strong message, even if we are not yet sure who is behind it.”

The Congolese authorities are investigating the attack, Mende said.