Two persons were killed on Friday when some cylinders exploded in an industrial area in Jammu and Kashmir, authorities said.Amar Singh and Sant Ram, both employees of the Border Roads Organisation, died when two acetylene cylinders in a truck exploded, a police officer told IANS here. The truck had gone to fetch oxygen cylinders from a factory in Bari Brahman industrial area when the acetylene cylinders burst, sparking more explosions.