An explosion of ammonia gas in the recovery department of the Saraswat Co-operative Bank in Somwar Peth left four persons injured on Wednesday afternoon. According to the police,employees of the Snow Line Company were filling ammonia gas in the compressors of air conditioners at the bank. While work was on at the recovery department located in the basement of the building,the explosion took place around 2.30 pm. The impact was so severe that the glass door at the entrance to the bank shattered into pieces. Two employees identified as Samir Dighe (30) of Erandwane and Santoshkumar Bharti (25) of Warje received major burns. They were rushed to the KEM hospital for treatment. Besides,two bank employees Pradip Kumbhar and Naresh Pradhan were also injured in the incident. Meanwhile,bank officials called in the fire brigade and police. Police inspector Marutrao Daphale of Samartha police station and inspector Suhas Nadgauda of Bund Garden police station visited the spot.