MUMBAI- An Indian navy officer has been killed in an accident on board a ship under construction at a dockyard in Mumbai. According to the Indian journalists, the destroyer had been undergoing mechanical trials when a blast on board led to a toxic gas leak. An increase in accidents over the past seven months; has put a question mark over the Indian navy. On February 26, 2014 the Navy Chief Admiral D K Joshi quit after two officers died battling a fire on board the submarine, INS Sindhuratna. In August last year, an explosion inside another submarine, INS Sindhurakshak, killed 18 sailors. In 2011, a frigate sank after colliding with a merchant vessel.