Hundreds of Bangladeshis took to the streets on Saturday for the second day of demonstrations following the death of a writer in a tight security prison in a case that worried countries around the world.

The demonstrators toured Dhaka University, chanting slogans denouncing the government's treatment of Mushtaq Ahmed, and other opposition writers, journalists and activists.

Another event was held at the National Press Club.

The protesters demanded the abolition of the strict digital security law, under which Ahmed was arrested and imprisoned. This law has often been used to suppress dissent since it was enacted in 2018.

Clashes took place between security forces and students in Dhaka on Friday night. Police announced the arrest of six people, while activists said at least 30 people were wounded.

Ahmed collapsed and died in Chaimpour prison late Thursday. He was arrested in May after criticizing the government's handling of the COVID-19 pandemic.

The 53-year-old is known for his satirical style and also has a crocodile farm. He was charged with spreading rumors and carrying out "anti-state activities."

The protesters described his death as an "assassination during detention" after his request for conditional release was rejected six times in 10 months.

"Ahmed's death was not normal. We will say it was an assassination," said one of the protesters, Manisha Shkraborty, who belongs to a left-wing group.

The demonstrators said they would go to Prime Minister Sheikh Hasina's office carrying a coffin, later Saturday.

Faced with questions about the issue from countries around the world, the authorities ordered an investigation into Ahmed's death, a prominent government official, SM Tarik Al-Islam, told AFP.

"We have formed a committee to investigate whether there was negligence on the part of prison officials or in the procedures for his treatment," the official emphasized.

Ambassadors of 13 countries, including the United States, France, Britain, Canada and Germany, expressed their "grave concern."

"We call on the government of Bangladesh to carry out a prompt, transparent and independent investigation into all the circumstances that led to the death of Mr. Mushtaq Ahmed," the ambassadors said in a statement released late Friday.

They affirmed that their countries will pursue "broader concerns about the provisions of the Digital Security Law and its implementation, in addition to questions about its compliance with Bangladesh's obligations with international human rights laws and standards."

Rights groups have also voiced concerns about the issue.

The New York-based Committee to Protect Journalists called for a "prompt, transparent and independent investigation," while the "Pin America" organization stated that the authorities should drop the charges against Kabir Kishore, the cartoonist who was arrested along with Ahmed.

The Committee to Protect Journalists said that Kishore delivered a letter to his brother during this week's hearing stating that he had been subjected to severe physical abuse during police custody.