Congo sealed its border with Uganda on Saturday to cut off a rebel group's supply line, government officials said. Although rebel leader Laurent Nkunda signed a peace deal with the government in January, fighting in the east of the country soon resumed. On Thursday, Nkunda's rebels and army soldiers exchanged machine-gun and mortar fire in one of their fiercest battles this year. "The government has closed this border in order to cut off the rebellion of Laurent Nkunda from its supply source," said Foreign Ministry Spokesman Claude Kamanga Mutond. "We want to stop Nkunda from being able to supply himself to continue this war." Nkunda, an ethnic Tutsi, claims he took up arms to protect Tutsi villagers from the Hutu extremists who invaded eastern Congo from neighboring Rwanda at the end of that country's 1994 genocide. The Hutus, who led the genocide of more than half a million Tutsis in Rwanda, were eventually pushed over the border into Congo.