India, Nov. 22 -- At least 20 people were killed and several injured following a explosion in a chemical factory in Pakistan's Punjab province on Friday, officials said. The incident took place in the morning in the Faisalabad district of Punjab, some 130 km from Lahore. A report of the district administration on Friday morning said the incident took place early after a boiler at the factory exploded, causing the collapse of the nearby structures. However, the Punjab Emergency Services Rescue 1122 and Faisalabad Commissioner Raja Jahangir Anwar later attributed the explosion to a gas leak. According to Anwar, four factories were operating in the Malikpur area of Faisalabad when a fire erupted in one of the factories due to gas leakage and e...