AL-MUKALLA: The explosion which crippled a French supertanker off Yemen could not be due to a technical fault, the ship's captain, Hubert Ardillon, told reporters here on Tuesday. "The way the explosion happened it could not be due to a technical problem," Ardillon said. "A member of the crew told me he saw a small boat approach and I believe him." A US official said on Monday that initial evidence suggested that Sunday's explosion that crippled the Limburg was accidental, as Yemen has claimed, and not terrorism.