At least 20 passengers were killed and many others were missing as a boat carrying 40 people capsized in the Ganga river near here on Saturday evening, officials said. Only eight people were rescued so far.The bodies of 20 passengers have been recovered, while eight people are being treated at the Patna Medical College and Hospital, said Patna SSP Manu Maharaj.According to eyewitnesses, the overcrowded boat was returning from a kite flying festival, organised as part of Makar Sankranti by the state Tourism Department, when the incident took place around 6 p.m.Rescue operations were hampered since it was already dark by the time. Six of the eight people rescued were pulled out from the river by the National Disaster Response Force, a team of which was deployed for the rescue operations. Patna District Magistrate Sanjay Agarwal and district police officials are camping at the site.Bihar Chief Minister Nitish Kumar has ordered a probe into the incident.The state government also announced an ex-gratia of Rs 4 lakh to the next of the kin of the victims.Meanwhile, the ruling JD-U postponed its state President Vashisht Narain Singh's Makar Sankranti feast planned for Sunday.