Six crewmen were reported missing after an oil tanker was believed to have exploded and capsized at 4.6 nautical miles off Tanjung Pengelih near Pengerang, early today.

All the missing crewmen were Indonesians identified as Akhmad Faharuddin, 35; Muhamad Heri Hernanda, 28; Raden Abdur Rahem, 31; Rendy Alamanda,28; Sulkifli, 39; and Yohanis Sumari, 35.

Malaysian Maritime Enforcement Agency deputy director-general (Operations) Rear Admiral Datuk Mohd Taha Ibrahim said the tanker, MT Putri Sea, was laden with crude oil and was registered at the Port of Malabo, Equatorial Guinea.

"The ship is 46.4 metres long and has six crewmen of Indonesian nationals aged between 28 and 39," he said in a statement here today.

He said the MMEA received a notification about the missing oil tanker from the Singapore Police Coast Guard (SPCG) at about 5 am after the agent failed to contact the ship.

"A Penggalang 15 boat from Tanjung Sedili Maritime District was deployed to run a check and arrived at the location at 6.15 am, but no ship was sighted," he said.

However, Mohd Taha said there were signs of oil spill around the area.

The search and rescue operation to find the missing tanker and its crewmen was launched at 12.30 pm involving Penggalang 15 boat from Tanjung Sedili, Al-Nilam ship from Marine Department and two boats from Johor Port, he added.