An explosion and fire at an Exxon Mobil refinery in Torrance, California, the US, has injured four workers.

The fire, which exploded at a gas processing unit, has shattered windows of nearby buildings, reported Reuters.

The company is currently investigating the reason for the blast. Following this incident, the 155,000-barrels-per-day refinery is likely to remain shut for months.

Torrance Fire Captain Steve Deuelwas quoted as saying by the news agency that there was no proof of foul play.

United Steelworkers Union Local 675 secretary and treasurer Dave Campbell was quoted as saying by The Wall Street Journal that as per the reports from workers, the fire might have been started at the refinery’s fluid catalytic cracking unit.

The refinery, sprawling over 750 acres, is located about 20 miles south of downtown Los Angeles and has approximately 1,000 employees.

It has an annual production capacity of 1.8 billion gallons of gasoline, which accounts for close to 8.5% of the total refining capacity in the state, reported The Associated Press.

The Wall Street Journal cited Oil Price Information Service energy analysis global head Tom Kloza as saying that the blast at the refinery had lead to increase in spot price of gasoline in the local market by nearly 12 cents to close at $2.01.

Recently, Warren Buffett’s Berkshire Hathaway divested its stake in Exxon Mobil for $3.74bn due to concerns over plunging oil prices.