A 20-year-old man was arrested on Saturday in connection with the alleged rape and murder of a teenage girl in West Bengal's North Dinajpur district that triggered violent protests, police said.

The 17-year-old girl, whose body was found in a canal in Kaliachak police station area on Friday, knew the man, Superintendent of Police (SP) Md Sana Akhtar said, identifying him as the prime accused.

A case has been filed under IPC section 302 (murder) and relevant sections of the Protection of Children from Sexual Offences (POCSO) Act based on the complaint filed by the girl's mother, he said.

The preliminary post-mortem report revealed no injury to the body, Akhtar said, adding that a bottle of poison was found near the body.

"We are investigating the case from all angles," he said.

Violence rocked Kaliachak, around 18 km from the Bangladesh border and 320 km north of Kolkata, as locals protested against the incident, prompting the police to use tear gas shells and charge batons to bring the situation under control, officials said.

Several shops and e-rickshaws were set on fire by the mob, which demanded the arrest of those behind the incident. Roads were also blocked and stones were hurled at the police, they said.

The RSS-backed ABVP gheraoed the Kaliaganj police station, while BJP state president Sukanta Majumdar sat on a dharna outside the SP office in Raiganj, demanding justice for the victim's family.

Rapid Action Force (RAF) was deployed to bring the situation under control, police said, adding that a few protestors were also detained.

Three persons were injured in the police action and admitted to the Raiganj Government Medical College and Hospital, officials said.

Majumdar, who visited the victim's village along with local BJP MP Debasree Chaudhuri, demanded a CBI investigation into the incident.

"We think the real truth will be revealed only if a CBI inquiry is conducted in this case," he told reporters.

The National Commission for Women (NCW) also sent a team to the area, and sought a report from the state police within three days.

The girl went missing on Thursday evening after she left home for going to her tuition classes. Her body was found the next day floating in a canal amid hectic searches by her family and locals.

Protests had started on Friday afternoon but quietened down by the day-end, only to restart on Saturday.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.