(corrects duration in 4th para to 12 days) ARGUINEGUIN, Spain, Sept 3 (Reuters) - Thirteen African migrants were found dead on a fishing boat intercepted by police off Spain's Canary Islands, the Spanish Red Cross said on Wednesday. There were 46 survivors and a Red Cross spokesman told Spanish radio they were too confused to give details of exactly what took place. Police intercepted the boat about 2 km (just over one mile) off the port of Arguineguin at 8:30 a.m. (0730 GMT) on the island of Gran Canaria. Survivors' accounts differed but the group was at sea between eight and 12 days, the boat lost its way several times and the engine needed repair during the voyage, the provincial head of the Red Cross in Las Palmas told Spanish national radio. The 13 victims probably died from hypothermia, the Red Cross spokesman said. Among the survivors were two women and several children, a Reuters photographer at the scene said. (Reporting by Borja Suarez and Feliciano Tisera, writing by Sarah Morris; editing by Andrew Dobbie)