Gunmen have killed at least 136 people in an overnight raid on a camp for Congolese Tutsi refugees in Burundi, a UN spokesperson says. The Gatumba camp, near the border with DR Congo, provides shelter for 4,000 refugees who fled the country in June. A Hutu rebel group, the FNL, has claimed responsibility for the attack, which took place late on Friday. Men armed with machetes and guns attacked the camp, torching houses and leaving the scene littered with bodies. **Gunshots*** A UN spokeswoman in Burundi said another 30 people died later in hospital following the raid. The Hutu Forces for National Liberation (FNL) group said it had aimed to hit a military base, some 500 metres from the UN Gatumba camp, near the DR Congo town of Uvira. "Our target was a military camp near the refugee camp for Tutsi Congolese refugees," said FNL spokesperson Pasteur Habimana, quoted by Reuters news agency. "We then heard gunshots coming from the refugee camp aiming at us and then decided to retaliate." But some of the refugees known as Banyamulenge, who fled the Sud-Kivu region in eastern DR Congo, said the attack on the camp was deliberate. They cited unsigned leaflets circulated this week urging death to the Banyamulenge, reports say. The attack followed a two-day visit by one of the DR Congo's four vice-presidents, himself a member of the Tutsi community, to Burundi to speed up the process of repatriating the estimated 20,000 Congolese refugees.