YAOUNDE (Reuters) - At least 13 people including children died when a suicide bomber blew herself in a crowd that was fleeing an armed attack in northern Cameroon on Friday, a U.N. security report said. No group immediately claimed responsibility for the blast, or for the attack on the town of Mozogo in the Far North Region, near the border with Nigeria. The assailants struck early in the morning, firing guns into the air, according to the note seen by Reuters. “Frightened, the population fled into the park. It was at this point that a woman carrying an explosive charge allegedly entered the fleeing crowd and detonated her charge,” the note said. Victims included men, women and children, it added. Fighters from the Boko Haram militant group, which had been trying to carve out an Islamic caliphate in northeastern Nigeria for a decade, have launched attacks across the border in the past. There was no immediate comment from the government in Cameroon.