A fire broke out on a container ship sailing toward Singapore in the Indian Ocean, the Sri Lankan Navy said on Friday, a week after a cargo ship carrying tonnes of chemicals sank near the country's main port here nearly a month after catching fire.

Navy spokesperson Indika de Silva said the Liberian-flagged MSC Messina ship had left the port of Colombo on June 22 heading for Singapore and it caught fire outside the island's international maritime borders.