Students clashed with police in Bangladesh's capital on Friday as anger mounted at the death of a writer and government critic in a high-security jail.
At least 18 police and an unknown number of protesters were injured in the clashes, authorities and witnesses said, amid international demands for an independent investigation into the death of Mushtaq Ahmed.
An AFP correspondent saw police using batons and firing tear gas at students who staged a torchlight march calling for "justice" near Dhaka University.
Police said at least six students who allegedly attacked security forces with torches were detained. More protests were planned for Saturday.
Ahmed was arrested in May under the tough Digital Security Act -- that opponents say undermines freedom of speech -- after he criticised the government's handling of the coronavirus pandemic.
The 53-year-old, a crocodile farmer as well as a writer known for his satirical style, was charged with spreading rumours and conducting "anti-state activities" on Facebook.
Jail authorities said Ahmed fell unconscious and died on Thursday at the Kashimpur high-security prison outside of Dhaka.
He had not been suffering from a major illness, according to prison chief Mohammad Ghiasuddin.
- Tough security law -
Cartoonist Ahmed Kabir Kishore was detained at the same time and remains in custody. Both men had several bail requests turned down, the latest this week, and their treatment has faced mounting criticism.
Ahmed's lawyer demanded an independent inquiry into the death.
Thirteen ambassadors from countries including the United States, France, Britain, Canada and Germany also expressed "grave concern".
"We call on the government of Bangladesh to conduct a swift, transparent, and independent inquiry into the full circumstances of Mr. Mushtaq Ahmed's death," the ambassadors said in a statement.
They said there would be follow up approaches over "wider concerns about the provisions and implementation of the DSA, as well as questions about its compatibility with Bangladesh's obligations under international human rights laws and standards."
Rights groups have raised suspicions about the death.
The New York-based Committee to Protect Journalists also called for "a swift, transparent, and independent insvestigation", while PEN America said that Bangladesh authorities should also drop charges against Kishore.
"Not only should Ahmed have never been detained for his independent expression and critical views in the first place, his unjust death under the authorities' watch immediately followed his complaints of torture at the hands of the security forces," said PEN America's free expression expert Karin Deutsch Karlekar.
Ahmed's prosecution under the Digital Security Act was an example of the "worst form of repression", said Saad Hammadi of Amnesty International.
"No one should have to die solely for exercising their right to freedom of expression," he added.
Brad Adams, Asia director for Human Rights Watch, echoed that, saying: "Ahmed's death has sent a chill through Bangladesh civil society and should force the government into ending this peremptory treatment of peaceful criticism."
Around 2,000 cases have been filed under the law since it was enacted in 2018, according to Amnesty.
Many leading editors and senior journalists have been targeted for prosecution under the law.