CAPE TOWN—Hundreds of angry Congolese protested the deaths of three civilians during an exchange of fire between UN troops and M23 rebels in the eastern city of Goma on Saturday as security along the border with Rwanda deteriorated.

A woman and two children were killed Saturday morning in Goma, the capital of the Democratic Republic of Congo’s North Kivu province, located just across the Rwandan border.

“The atmosphere is very tense,” said Lieutenant Colonel Felix-Prosper Basse, spokesman for the UN peacekeeping mission in Congo.

“The new attacks won’t go unpunished,” Basse said. “It is unacceptable to target civilians.”

The newly deployed UN forces were responding to the shelling of Goma by M23 rebels, which started Wednesday.

Saturday’s deadly shelling occurred a few hours after Congo’s government accused Rwanda of firing eleven mortars into its territory, injuring 12 civilians. Rwanda denies the allegations.

Authorities in Congo, along with countries such as United States, accuse Rwanda of providing support to the M23 rebels in order to undermine Congo’s government.

The Rwanda Defense Force called for an investigation of a bombing of Rwandan villages by Congolese forces. Five mortar bombs hit four villages in Western Rwanda that border the Congo’s volatile East Kivu region on Friday afternoon, the RDF said in a statement.

The Rwandan government has asked the UN “to investigate the provocative bombing,” RDF spokesperson Brigadier Gen. Joseph Nzabamwita told dpa.

“The continued indiscriminate bombing of Rwandan villages by DRC armed forces is unacceptable and must stop immediately,” he added.

In February, Congo and Rwanda signed a UN-backed Peace, Security and Cooperation Framework to stabilize the region.

The ongoing unrest in eastern Congo has forced about 800,000 people to flee their homes.

The United Nations has been deploying a 3,000-soldier intervention brigade in eastern Congo since July, which is the first UN force ever with a mandate to actively rout out rebel groups. The new brigade bolsters the regular 18,000 UN peacekeepers, who have a mandate to protect civilians.

The peacekeepers were in the process Saturday of coordinating a military response with Congolese military authorities to return calm to Goma and ensure the protection of civilians, Basse said.

“We will make sure attacks on civilians won’t happen again,” he said. “We are there for them.”

The peacekeepers have been trying to fight back the M23 short for Movement of March 23 for the past 16 months.

The rebel movement was formed in April 2012 when nearly 300 soldiers, mainly from the Tutsi community, turned against Congo’s government, citing poor conditions in the army and the government’s unwillingness to implement a March 23, 2009, peace deal.

In November, the M23 briefly captured Goma, withdrawing in exchange for a series of demands, including negotiations with the government.

A peace deal has remained elusive.

• MCT Campus