A South Korean fishing boat exploded Thursday, killing five people and injuring 13 others, in an apparent ammonia leak in the port of Montevideo, Uruguay, said the Foreign Ministry. Twenty-four sailors were working on the 435-ton squid fishing boat, the 101 Seaworld, when the blast took place, a ministry official said. The ship had 35 crew members from South Korea, China, Vietnam and Indonesia were killed, he said. Among the dead are three Koreans and one Vietnamese. The injured mostly suffered from respiratory problems. Ammonia is often used as a coolant in the refrigerated section of fishing boats to prevent fish from rotting. The incident is the second mishap in as many days involving South Korean ships abroad. On Wednesday, a 1,994-ton South Korean cargo ship disappeared 23 kilometers off the coast of Japan amid turbulent weather. Two survived and three bodies have been retrieved, while a search continues for six others still missing. -- SPA