five workers were killed on the spot while seven others sustained severe injuries after a boiler in alpha packaging factory at silvassa union territory exploded on wednesday afternoon.sources said that the company does packaging for a multinational company at ambli village in silvassa. the blast took place in the afternoon, when welding work in boiler was under progress. around 10 people who were nearby were severely injured and a nearby wall of the factory collapsed. the neighbouring buildings and factories also experienced tremors following the explosion.people gathered to the spot and were shocked to see human body parts lying in different places. silvassa police also reached the spot after learning about the incident and started investigations. those injured were immediately rushed to a nearby hospital for treatment.the fire department officials and a medical team from a government hospital also rushed to the spot.silvassa police inspector k b mahajan along with his staff reached the spot and started probe after everything was under control. police had lodged an accidental death complaint in this connection. forensic officials also have started probe. police sources said that five people succumbed to severe injuries on the spot.after primary investigations, silvassa police inspector k b mahajan said, &ldquothe repair work in the boiler was under progress and two youths were carrying out welding work in the factory premises. the factory owner stays in mumbai and a manager looks after the packaging work. at present the casualty figure has reached five people. seven others are injured, some of them in a critical condition. the identification of the deceased is in progress.&rdquo