TNN, Chennai : An overcrowded ferry with 45 passengers, most of them tourists, keeled over and sank off Viper Island, 500 metres from the dockyards in Port Blair in the Andaman & Nicobar Islands, killing at least 21 people around 4pm on Sunday. The diesel-run tourist boat Aqua Marine had covered a distance of barely two nautical miles from where it started on Ross Island when it sank. The vessel took in water rapidly after the plank broke, according to sources. Thirteen people have been rescued so far and 11 people are missing. Most of those killed were elderly and children, said sources. There were only 25-odd life jackets on board, and many passengers didn’t even have these on when the ferry listed. Government sources said the privately-owned boat had a capacity to carry 25 people, but was carrying 45 passengers. Some people might have been trapped in the cabin of Aqua Marine, it is learnt. The dead included 11 women and a seven-year-old girl. Thirteen of the dead were from Kancheepuram in Tamil Nadu, three from Chennai, three from Mumbai, one from Kolkata and one from Saharanpur in Uttar Pradesh. Most of the occupants of the boat arrived in Port Blair on Thursday on a package tour. Officials said rescue operations began soon after the boat sank, with people on Viper Island alerting the police. Nearly 50 policemen and divers from the Coast Guard took part in the rescue. “The boat crew took 10 extra passengers just before it left the jetty at Ross Island. The boat was already carrying 35 people including crew,” said Gajendra Kumar, a tourist and DSP, Kancheepuram. He was rescued along with his wife.