A blogger who had been critical of Bangladesh's Islamist groups was killed in the capital late on Friday, police said, a day after he attended a big rally against leaders of the country's largest Islamic party.
Protests championed by the country's bloggers have seen thousands of people take to the streets demanding the execution of leaders of the Jamaat-e-Islami party who are under trial for war crimes.
Clashes between police and Islamist protesters demanding the trials be halted have also rocked the capital.
Police found the body of Ahmed Rajib, 35 -- better known by his online identity Thaba Baba -- near his home in Dhaka's Pallabi suburb, with his head hacked apart with a machete.
"We recovered the machete. It is clear the attacker wanted to murder him. They did not touch his laptop or other valuable objects," police official Sheikh Motiur Rahman told AFP.
Police have not commented on a possible motive for the killing, but Rahman, citing Rajib's relatives, said the blogger played a large role in organizing the anti-Islamist protests.
Rajib's brother, who declined to be named, told AFP his sibling had been "threatened frequently" by Islamists angry at his role in the protests and his writings against the religion.
"In recent months he stopped writing against Islam and concentrated on the war crime issues," he added.
At least 13 people have died during clashes over the ongoing trials in which a host of senior Jamaat figures -- including the party's leader and deputy leader -- are being tried over their role in the 1971 independence war.
The clashes have intensified since last week after a senior Jamaat leader was sentenced to life imprisonment for mass murder.
Jamaat and the main opposition Bangladesh Nationalist Party have said the trials are based on bogus charges and part of a wider political vendetta.
The government says the trials are needed to heal the wounds of the nine-month war in which it says three million people were killed, many by pro-Pakistani militia whose members allegedly included Jamaat officials.
The killing late on Friday was the second fatal attack in Dhaka against a blogger critical of Islamist groups in less than a month, after the stabbing death of a self-styled online "militant atheist" by three unidentified men near his office in the upscale Uttara district.