FREE TOWN (Reuters) - At least 70 people, mostly children returning from their school holidays, died when a boat carrying 150 passengers capsized in a heavy storm off Sierra Leone, police said on Wednesday. Most of the dead were children between the ages of eight and 16 years old, Sam Bangura, a senior police officer, told Reuters in response to inquiries, adding that police had found 24 survivors from the accident on Tuesday. Bangura said the police were still searching for survivors of the incident, which took place near the Tombo suburb of the capital Freetown and was caused by the boats engine failing as it drifted into a heavy storm. Abu Essay, one of the survivors, said most of the victims were children returning from the town of Waterloo, 12km away from Freetown, where they had spent their school holidays. Lack of maintenance and overcrowding mean that boat accidents are frequent in West Africa, which is currently being battered by seasonal storms and heavy rain that on land have already killed more than 160 people and displaced thousands more.