KUALA LUMPUR, May 4 ― Velesto Energy Bhd is investigating the incident involving its drilling rig, Velesto Naga 7, which submerged today in offshore Sarawak, and is evaluating options.

"The rig is covered by insurance and recovery efforts are ongoing and being monitored,” it said in a filing with Bursa Malaysia.

The offshore drilling services provider said the incident occurred at the worksite due to rapid penetration into the formation on Monday while operating for a client.

The rig tilted and subsequently submerged at the location today.

Velesto said drilling activities had not started and no well had been drilled.

"All personnel on-board are safe on the rescue vessels, and the majority have been transferred to Miri, Sarawak. The remaining personnel are in the process of being transferred,” it added. ― Bernama