KATHMANDU: A Nepal Airlines aircraft spilled a huge quantity of fuel while undergoing regular maintenance at the Tribhuvan International Airport on Tuesday evening.

According to a source at the country's sole international airport, approximately 6,000 litre of jet fuel spewed from the Airbus 320 aircraft when a team of maintenance engineers tried to change a fuel pump at 7:00 pm.

"As a large section of parking bay was covered by the leaked fuel, an emergency response team was deployed there with necessary foams and flushing equipment," an eyewitness said.

The 9N-AKW aircraft has been grounded at TIA since yesterday for want of new fuel pump.

There could have been some procedural errors by the maintenance team while dealing with the valve, a source added.

A team from the Civil Aviation Authority of Nepal (CAAN) immediately visited the scene and has also issued an order for investigation.

"NAC will come up with preliminary report after inquiring the maintenance team involved in the fuel spill incident tomorrow," an official said.