At least 3 persons drowned after a boat overturned in Mahananda river in Bihar (Representational image)

At least three persons drowned while more than 20 others went missing after a boat carrying close to 80 people overturned in the Mahananda river in Bihar's Katihar district, police said on Friday.

Senior police officer of Police, Barsoi, Pankaj Kumar said the incident took place on the Bihar-Bengal border at about 8.15 pm on Thursday night close to Jagannathpur Ghat when residents of Wajidpur village here were returning after shopping in Rampur Haat market of the adjoining state, situated right across the river.

"Prima facie, it appears to be a case of overloading. The boat had a capacity of 40 passengers but was carrying almost double the number. So far three unidentified bodies of an elderly man, a woman and a child have been recovered," the senior police officer said.

"Many of those riding the boat either swam to safety or were rescued by onlookers. About two dozen people are yet to be traced ... professional divers have been deployed for the purpose," he added.