Fighters who backed former Ivory Coast president Laurent Gbagbo have infiltrated refugee camps in Ghana and are accused of attacking security bases back in Ivory Coast, according to Ivorian officials.Human rights groups say the presence of Gbagbo’s ex-fighters in the camps poses a threat to the security of refugees.Some fighters had been allowed to slip into the three refugee camps housing Ivorians, said Tetteh Padi, program coordinator of Ghana’s Refugee Board. In one example, Ghanaian authorities in May lost track of nearly 150 suspected fighters who were supposed to be transferred to a maximum security prison and now their whereabouts are unknown."We have known for a fact that some of them have infiltrated the camps,” said Padi. "Some of them have friends, relatives in the camps. So they have gone in there unofficially.”Ghana’s failure to monitor the ex-combatants is very worrying, said Matt Wells, West Africa researcher at Human Rights Watch."Ghanaian authorities appear to have dropped the ball in losing track of many Ivorian ex-combatants, putting civilians in refugee camps at risk of sexual violence and child recruitment, among other protection concerns,” Wells said. Ivorian President Alassane Ouattara’s government alleges that Gbagbo fighters in the camps have taken part in recent attacks on military positions in Ivory Coast. Since early August, about 10 such attacks have been carried out throughout the country, with some allegedly perpetrated by fighters based in Liberia as well as Ghana.One attack on a town at the border between Ivory Coast and Ghana in September prompted Ivory Coast to close its land and sea frontiers with Ghana for more than two weeks.However, Padi said accusations that fighters in refugee camps had been involved in the attacks are baseless."They’re totally false in our opinion because we know everything that goes on in the camps,” he said.Ampain, the largest of the three refugee camps for Ivorians in Ghana, is a sprawling, unfenced facility now home to some 4,000 people.Ghanaian authorities refused to allow The Associated Press to visit the refugee camp and deleted photos taken by a reporter who interviewed Ivorians living there.Patricia Ange Oulai, a 29-year-old refugee in the camp, said the presence of the fighters had her worried for her safety. "I regret that they are here because with everything happening people think they are the ones that are going to do the coup” back in Ivory Coast, she said.Post-election violence erupted in Ivory Coast after Gbagbo refused to cede office despite losing the November 2010 runoff vote to Ouattara. Agencies