South Sudan’s main rebel force SPLM-IO has accused government forces of attacking their defensive positions a day after both sides signed a peace deal, while the U.N. mission said one of its peacekeepers was shot and wounded by a government soldier.

President Salva Kiir signed a peace agreement with rebel factions in the Ethiopian capital on Wednesday to end a civil war that has killed at least 50,000 people, displaced some three million and held up the country’s progress since it gained independence seven years ago.

“The regime’s forces heavily stormed our position at Mundu in Lainya county,” said Lam Paul Gabriel, the rebels’ deputy military spokesman, in a statement seen by Reuters on Saturday.

He said the attack happened in the early hours of Friday and that eight government troops were killed in the ensuing battle. Another attack took place in Mangalatore, near the site of the first attack, where four government soldiers were killed, the statement said.

Both Mundu and Mangalatore are in Yei River State, close to the border with Uganda.