They discovered that a bag in the overhead lockers was emitting both smoke and sparks and tackled it with fire extinguishers.

They then discovered a laptop that had overheated and was the source of the smoke so put it in a container filled with water. The aircraft continued the flight to Bangalore and landed safely.

India's Director General of Civil Aviation has been informed about what happened.

AvSax fire containment bags are now on board several major airlines worldwide.

They have been deployed on aircraft 20 times so far this year and means they don’t need to make an emergency landing and continue the flight confident the bag has solved the problem. The average cost of an emergency diversion in the USA is $400,000.

If an electronic device starts to seriously overheat or emit smoke the cabin crew will pour at least two litres of water into an AvSax and then drop the burning device into the bag, adding additional water as required. The water activates the polymer gel inside the bag causing it to expand around the device. Should the device keep on venting then the AvSax is tough enough to absorb the force.

The AvSax cools the batteries in the device, reducing the likelihood of the battery catching fire but if it does go into thermal runaway it is all contained within the bag.

Amazingly, the water is absorbed into the internal lining of the bag so the device is dry when it is removed.