Image copyright EPA Image caption Ananta Bijoy Das was stabbed to death in the street - in daylight, on his way to work in a bank

A secular blogger has been hacked to death in north-eastern Bangladesh in the country's third such deadly attack since the start of the year.

Ananta Bijoy Das was attacked by masked men with machetes in Sylhet, police say. He is said to have received death threats from Islamist extremists.

Mr Das wrote blogs for Mukto-Mona, a website once moderated by Avijit Roy, himself hacked to death in February.

Sweden has confirmed it turned down a visa request from Mr Das in April.

He had been invited to attend a press freedom event by the Swedish Pen writers organisation but officials in the country's embassy in Dhaka refused the request, citing a risk he might not return home.

Swedish Pen told the BBC they were in the process of submitting an appeal when they heard of Mr Das's murder. The group has demanded an explanation from their government, the BBC's John McManus reports.

Media playback is unsupported on your device Media caption Binoy Vadra, friend and fellow blogger: "We don't know if police will protect us"

Witnesses said four attackers killed Mr Das in broad daylight near his home as he headed to work at a local bank.

Local police officer Mohammad Rahamatullah told Reuters that Mr Das "came out of his house and what we came to know from the local people who are witnesses, was that four miscreants chased him and killed him near his house".

The attackers fled. Mr Das was taken to hospital but declared dead on arrival.

Analysis: Akbar Hossain, BBC Bengali service

Police say there are similarities in the way all three bloggers were killed - hacked to death with sharp weapons. In each case, attackers carried out their plan on a busy street.

Death threats to secular bloggers are on the rise in Bangladesh. A few years back, hardline Islamists demanded a blasphemy law to stop bloggers they perceive to be anti-Islamic from writing about Islam.

Secular forces in Bangladesh say that their views are under threat. Intolerance is growing as the country's politics increasingly diverge into secular and non-secular poles.

Bangladesh is officially secular. But critics say the government is indifferent to the problem of blogger killing - pointing out that no-one has yet been punished for any of the attacks.

Clear pattern to blogger killings

The bloggers killed for their beliefs

Fellow writers said Ananta Bijoy Das had been on a list of targets compiled by Islamists who were behind the February murder of Avijit Roy.

Mr Roy, a Bangladeshi-born US writer, had criticised religious intolerance before his murder in Dhaka.

He was killed in a machete attack while returning with his wife from a book fair in the city. His widow suffered head injuries and lost a thumb.

In March, another blogger, Washiqur Rahman, was hacked to death in Dhaka.

Image copyright Reuters Image caption Avijit Roy was known for his writings against religious fundamentalism

Image copyright Reuters Image caption Mr Roy's widow, Rafida Bonya Ahmed, lost a thumb in the February attack

Sara Hossain, a lawyer and human rights activist in Dhaka, told the BBC that Mr Das and Mr Roy were on a list of targets.

"They've always believed and written very vocally in support of free expression and they've very explicitly written about not following any religion themselves," she told the BBC World Service's Newsday programme.

"These last two have been part of a blog called Mukto-Mona [Free Mind], which is about free thinking and is about explicitly taking on religious fundamentalism and particularly Islamic religious fundamentalism. Their names have been on lists of identified targets."

The attack on Mr Roy prompted massive protests from students and social activists, who accused the authorities of failing to protect critics of religious bigotry.

An Islamist has been arrested over his murder, while two madrassa students have been arrested over Mr Rahman's killing.

Shame - and a warning

Social media users are paying their last respects to blogger Ananta Bijoy Das, with some expressing shame and regret. However, others express jubilation.

"Sorry to you Dada! [a term of endearment denoting elder brother]," one user posts on Mr Das's Facebook page while another says: "We could not save you."

A typical comment voiced by many says: "We are ashamed."

On Twitter, prominent blogger Imran H Sarker writes: "No Justice, impunity!", while blogger Rezwan uses the hashtag #Wordscannotbekilled in his tweet.

Some accounts apparently linked to a militant Islamist group are posting messages claiming responsibility and celebrating the killing.

"What a blessed news to wake up to? We won't let the kuffar [term used to refer to non-believers] sleep comfortably in their mansions!!" one tweet says.

"Stay tuned for next target... " another warns.

BBC Monitoring reports and analyses news from TV, radio, web and print media around the world. You can follow BBC Monitoring on Twitter and Facebook.