About 30 unidentified people assaulted an M23 rebel position early today five miles (eight kilometres) from Goma in Congo's North Kivu province, spokesman Martin Nesirky said.
The M23 rebels counter-attacked, and as the assailants retreated they fired shots at the UN peacekeepers' post, Nesirky said.
"In accordance with their rules of engagement, the peacekeepers fired warning shots before being forced to engage the attackers. In the firefight that ensued, four attackers were injured" and captured by the peacekeepers, Nesirky said. He says they were treated on the scene and evacuated to a Goma hospital.
The fighters routed government forces and swept past UN peacekeepers last November, briefly occupying Goma, one of eastern Congo's biggest cities. They withdrew only after the government agreed to negotiate.
Trying to separate multiple armed groups in the region and protect civilians is the 22,000-strong peacekeeping force MONUSCO.