An investigation is under way after an explosion rocked a remote section of Malaysian national oil company Petronas’ 600-kilometre Sabah Sarawak Gas Pipeline (SSGP) on the island of Borneo on Monday morning.

"We confirm that a pipe rupture and a fire incident have occurred at the Sabah-Sarawak Gas Pipeline at 1:59AM (local time) today approximately four kilometres from Long Selulong, Ulu Baram, Miri," said Petronas.

"The fire has been put under control and we are closely monitoring the situation."

The latest blast happened close to the remote Penan settlement of Long Kawa about eight hours by road from the oil town of Miri.

"I am not sure yet what was the cause. Petronas technicians are on the way there to find out the latest situation,” Telang Usan state assemblyman Dennis Ngau told The Star

"A senior Petronas officer told me that there are no injuries."

The Sarawak Fire and Rescue Department has reportedly also deployed a team to the site.

"We would like to inform that no injuries were reported," added Petronas.

"The relevant authorities have been notified and we will continue to engage with the communities in the surrounding area.

"An investigation on the incident is currently ongoing and we wish to assure the public that safety of the people and environment remains our utmost priority and concern."

This is the fourth known explosion or fire that has occurred on the Sarawak state section of the multi-billion dollar SSGP that delivers feedstock from fields in Sabah to the Petronas LNG Complex at Bintulu.

Earlier incidents include a fire that broke out last May in Lawas district and the January 2018 explosion near Long Luping, close to the state border, which forced locals to flee their homes.

“Petronas adheres to stringent safety measures in line with international standards at its areas of operations,” the company said at the time of the May 2019 gas leak and fire.

Penans - aboriginal hunter-gatherers - seven years ago had protested and set up blockades during construction of Petronas SSGP project, which they claimed was affecting their lands and livelihoods.