FILE PHOTO: A worker rides a bicycle at the Bharat Petroleum Corporation Ltd. refinery in Mumbai, India April 24, 2008. REUTERS/Punit Paranjpe/File PhotoReuters

A hydrocracker unit of Bharat Petroleum Corp. Ltd (BPCL) in Mumbai was shut down on Wednesday following a massive fire that left at least 43 people injured.

"We have shut the hydrocracker and assessment will be done on Thursday to know how long we need to keep it shut," R Ramachandran, the head of refineries told Reuters. The remaining units will remain open, he added.

The injured workers were admitted to Inlaks Hospital.

The incident occurred at 2.45 pm on Wednesday and around nine fire tenders were rushed to the spot. According to ANI, two jumbo tankers and two foam tenders were also sent.

The fire brigade chief, PS Rahangdale, said that the firefighting operation was not easy due to extremely high heat and pressure inside the plant. The fire had broken out in the compressor shed of the plant.

"A fire occurred at BPCL Mumbai Refinery at Mahul plant today at around 1445hrs. The fire was in the Compressor shed of Hydrocracker plant. The fire is being fought by The Refinery firefighting team. The fire is still on but is under control," the BPCL said in a statement.

Locals reported that the explosion was so intense that it shook the windows of their buildings. "Its tremors shook windows of our building which is 500 meters away from the refinery," says a tweet by Santosh Aadhar.

Another tweet by Shantanu Misra reads, "Felt tremors and heard a massive blast like noise this afternoon near chembur. Got to know it's from the blast in BPCL refinery. Hope things are under control now chembur."

The refinery at Mumbai's Mahul-Chembur area was set up in 1955 and is BPCL's second-largest refinery. It has an installed capacity of 12 million tonnes per annum.