By Bernadette Christina and Fransiska Nangoy
JAKARTA (Reuters) -Indonesian state oil company Pertamina said on Monday it hoped to restore operations at its Balongan oil refinery in West Java in four or five days, as firefighters worked to extinguish a massive blaze that broke out overnight, injuring six people.
Pertamina shut the plant and evacuated about 950 nearby residents, with videos shared on social media showing huge flames engulfing the 125,000 barrels per day facility, while a large explosion could be heard.
Pertamina chief executive Nicke Widyawati told reporters the fire was concentrated in the refinery's storage tanks and there had been no impact on the processing plant.
"The main equipment at the refinery is not affected," she said. "We hope the plant can be operational again soon after we put out the fire so there are no disruptions to supply."
Separately, Nicke told local media that only four storage tanks were affected, out of the total 72 tanks in Balongan with total capacity of 1.35 million kilo litres.
Efforts to estinguish the blaze were continuing, she said, adding that the fire had been contained to a small area and she's optimistic it will be put out soon.
Pertamina expects operations can be restored in four to five days, Pertamina director Mulyono said.
The fire started just after midnight during bad weather, Pertamina said, although the cause was currently unknown.
Six people were being treated in hospital for burns, a company statement said. No Pertamina staff were hurt.
FUEL STOCK "SECURE"
Pertamina's Mulyono said the company had "secure" levels of fuels stocks to supply Indonesia, including for the upcoming Islamic holidays of Eid Al-Fitr.
"There is no need for panic because stock is abundant. This is of course because demand conditions are not fully normal yet, so the stock is still very high," Mulyono said.
Balongan, one of Pertamina's biggest refineries, supplies fuel to Jakarta and the western regions of Java island.
Pertamina will use fuel from its refineries in Cilacap and Tuban to help provide supplies to Jakarta while Balongan is shut, Mulyono added.
Television footage earlier showed a massive column of black smoke rising from the site, which is about 225 km (140 miles) east of the capital Jakarta.
Ahmad Dofiri, West Java police chief told local media that police suspected there was a leak at the site prior to the fire.
"Initial information we received is that there was a leak at the plant. While the leak was being handled, the lightning struck," Dofiri said, adding that police are looking into what ignited the fire.
Nicke said investigation is still ongoing.
A nearby resident told Metro TV she was awoken by a pungent smell of oil fumes and saw lightning strikes in the sky.
"We smelled a strong fuel scent first, so strong that my nose hurt, while we heard lightning strikes," said Susi, who gave only one name
"Suddenly the sky was orange," she said.
The refinery is expected to receive about 600,000 barrels of Rabi crude from Gabon onboard tanker Aristodimos on April 10, shipping data on Refinitiv Eikon showed.
(Additional reporting by Agustinus Beo Da Costa, Florence Tan; Editing by Ed Davies, Lincoln Feast, Richard Pullin and Louise Heavens)