JAKARTA (AFP) - Indonesian firefighters on Wednesday (March 31) extinguished a large blaze at one of the country's biggest oil refineries that had been burning for more than two days after an explosion rocked the facility.

Crews blasted fire-suppressing foam to quench the flames at two storage tankers after the inferno seriously injured at least six people early on Monday.

Thick plumes of black smoke shot into the sky at the Balongan refinery in West Java, owned by state oil company Pertamina.

The huge fire was eventually put out on Wednesday afternoon, the firm said.

"(The company) will continue to cool and monitor the tanks," Pertamina spokesman Agus Suprijanto said.

"Hopefully the cooling process will go smoothly and we can resume operations."

The cause of the fire was not clear, but the company said the blaze broke out during a lightning storm.

The local disaster agency said one person had died from a heart attack after the explosion.

Six severely wounded people have been hospitalised in the capital Jakarta, about 200km from the sprawling plant, which opened in the mid-90s and can refine some 125,000 barrels of oil a day.

At least 30 others suffered minor injuries.

Pertamina has insisted the fire is not likely to cause fuel supply disruptions due to a high volume of stock.