Ludhiana: Four persons were killed and 91 injured when a gas cylinder exploded and set off a fire in a hosiery factory in a residential area in Ludhiana on May 10, police said.

The injured were rushed to hospital where the condition of 15 of them was stated to be critical, they said.

The cause of the explosion which took place in Khud on May 10 afternoon, was being ascertained, police said.

PTI