SINGAPORE (Bloomberg) ? BW Group Ltd. said an oil supertanker caught fire in the Malacca Strait, killing four workers and injuring two.

A flash fire started in an empty cargo tank on the , a so-called very large crude carrier built in 1993, while contractors were working on the ship, the company said in a statement yesterday.

The ship, sailing from Singapore to Fujairah in the United Arab Emirates, called at Penang, Malaysia for medical assistance.

After an investigation by local authorities, the ship set sail at 1 p.m. local time to load its next cargo in the Middle East, the company said in a second e-mailed statement.

The is one of 25 very large crude carriers operated by BW Group, the world?s largest closely held shipowner.

Bermuda-based BW Group was created when World-Wide Shipping, started in Hong Kong in 1955 by Sir Yue-kong Pao, acquired Oslo-based Bergesen d.y. ASA in 2003.

The victims were members of a so-called riding squad, contractors who aren?t members of the ship?s crew and carry out work while a vessel is at sea. There were no reports of pollution or structural damage after the fire, BW Group said.