Three student protest leaders who helped co-ordinate the recent rallies in Bangladesh have been forcibly removed from hospital by police officers, the BBC understands.

Nahid Islam, Asif Mahmud and Abu Baker Majumder were taken from Gonoshasthaya Hospital in the capital, Dhaka, hospital staff said on Friday.

Staff members said the officers, who were dressed in plainclothes, had forced their discharge despite the misgivings of medics at the hospital.

The three men were being treated for injuries that they said were caused by torture and beatings they received in earlier police custody.

“They took them from us,” Gonoshasthaya hospital supervisor Anwara Begum Lucky told the AFP news agency.

“The men were from the Detective Branch.”

She added that she had not wanted to let the students go, but police had pressured the hospital chief to discharge them.

Mr Islam’s elder sister Fatema Tasnim told AFP from the hospital that six plainclothes detectives had taken all three men.

Nahid Islam told reporters last week he feared for his life.

He was kidnapped from a friend’s house last week, interrogated and subjected to physical and mental torture by people claiming to be detectives.

He says he fainted and when he regained consciousness, walked home and sought hospital treatment for blood clots on both shoulders and his left leg.

In response to his allegations, Information Minister Mohammad Ali Arafat told the BBC the incident would be investigated but that he suspected “sabotage” – that someone was trying to discredit the police.

Police have arrested more than 4,000 people since the unrest broke out last week.

All three students are members of Students Against Discrimination, the group responsible for co-ordinating this month’s street rallies against civil service hiring rules.

The trio’s student group had suspended a further wave of protests at the start of this week, due to the bloodshed.

At least 150 people have been killed as a result of nationwide clashes between police and university students, with security forces accused of using excessive force.

Protesters had been calling for quotas on government jobs to be scrapped.

Bangladesh had reserved about 30% of its high-paying government jobs for relatives of those who fought in the country’s war for independence from Pakistan in 1971.

Bangladesh’s top court has now rolled back most of these quotas and ruled that 93% of roles would now be filled on merit – meeting a key demand of protesters.

At the beginning of the protests the government imposed an unprecedented communications blackout, shutting down the internet and restricting phone services.

Earlier this week, Bangladesh’s leader Sheikh Hasina was accused of crying “crocodile tears” after she was photographed weeping at a train station that was destroyed during anti-government protests.

She has disregarded criticism that her security forces deploy excess force to quell the unrest, and instead blamed her political opponents for the wave of violence.

Some student leaders have vowed to continue protesting to demand justice for protesters killed and detained in recent days.

They are also seeking the resignation of government ministers and an apology from Ms Hasina.