Police have rescued a Rajshahi University student allegedly kidnapped from the campus on Friday.

Police also arrested the suspected kidnapper Sohel Rana, the victim's ex-husband, after raiding a marriage registration office in the capital's Rayerbazar.

Jamal Uddin Mir, officer-in-charge of Mohammadpur Police Station, said they raided the office around 3:00pm and found them inside.

"Sohel told police that they were married to each other, but the woman remained silent," the officer said, adding that the duo was handed over to Rajshahi police.

Sohel, a Dhaka University graduate currently practicing law at the Supreme Court, is suspected of kidnapping the student of Bangla department around 8:30am on Friday.

Witnesses said Sohel and some of his associates were in a white microbus parked in front of Tapashi Rabeya Hall of RU.

As the victim and some of her classmates came out of the dorm, Rana and a couple of men jumped out of the microbus and forced her into the vehicle.

The woman's parents said Sohel and she got married in December last year.

But she went to her village home in Naogaon in August and told her parents that her husband tortured her and asked for a dowry of Tk 25 lakh.

The parents added that she filed for divorce soon afterwards.  They also alleged that the suspect once attempted to kidnap her from their village home in September. They lodged a general diary with Mohadevpur Police Station at the time.

Her mother said Sohel was an addict and had been threatening them “with dire consequences" for the last couple of months.

Rana's father Joynal Abedin, a lawyer of Naogaon was arrested on Friday night.

Students, especially the women, demonstrated on the campus demanding safety.

"How can such crimes take place here while police are deployed?" Mahfuz Munna, a student of marketing, asked.

RU administration officials said they would meet civil society representatives and police to find ways to secure the campus.

A total of 150 police remain on the campus round the clock, where some 50 students have been killed in the last 44 years.