PETALING JAYA (THE STAR/ASIA NEWS NETWORK) - The eight suspects in the hijacking of Malaysian oil tanker MT Okim Harmony have confessed to the crime.

Malaysian Maritime Enforcement Agency deputy director-general (operations) Maritime Vice-Admiral Ahmad Puzi Ab Kahar confirmed that the suspects, who are all Indonesian nationals, had made the confession to the Vietnamese authorities.

Datuk Ahmad Puzi added that they were closely monitoring the situation, but declined to comment further.

The eight were arrested in Vietnamese waters near Tho Chu Island after they reportedly fled the MT Orkim Harmony in a rescue boat at 8.30pm on Thursday.

Before that, they had directed the Navy to move its ships about five nautical miles (9km) from the MT Orkim Harmony, threatening to harm the crew.

The vanishing act was only found out at about 1am on Friday when the captain of the seized oil tanker contacted the KD Terengganu.

The ship's captain did not inform the navy immediately of their escape as the pirates threatened to harm his family if he did so.

The tanker - owned by Magna Meridian Sdn Bhd and carrying 6,000 tonnes of petrol worth RM21 million (S$7.5 million) belonging to Petronas - had been reported missing since June 11 while on its way from Malacca to Kuantan Port, Pahang.

The vessel that was reported to be adrift in Cambodian waters then suddenly changed course to the east towards Natuna Island, Indonesia.

It had also been repainted and renamed 'Kim Harmon' by the pirates.

The oil tanker with 21 crew members arrived at Kuantan Port on Saturday morning.

One of its crew members, an Indonesian cook, was flown by helicopter to Universiti Sains Malaysia Hospital on Friday for treatment after he was shot in the thigh.