Image copyright AFP Image caption Professor Siddique taught English at the local university

The daughter of a Bangladeshi professor who was hacked to death in a murder echoing the killing of several secularists says he was not an atheist.

So-called Islamic State (IS) said it was behind the death of Rezaul Karim Siddique, who was killed on Saturday.

A statement from the militant group accused him of "calling to atheism".

But his daughter Rizwana Hasin told the BBC that her father believed in God, and that she had no idea why he was targeted.

"The investigators are investigating still, and we are still waiting to see the results," she said.

"We still don't know what was the reason. Maybe [a] misunderstanding, maybe something else. It's still a maybe for me and it's still a maybe for my family."

Siddique, 58, was a professor of English at Rajshahi University in the country's north-west. He was attacked with machetes as he left for work.

He founded a music school and edited a literary magazine, his family said.

Police believe he may have been targeted by extremists because he was involved in cultural activities. They have detained a member of an Islamist student organisation for questioning.

Hardline Islamist groups dislike anyone involved in the cultural field, the BBC's Dhaka correspondent Akbar Hossain says.

Image copyright AFP Image caption Rajshahi University held protests after the professor's death

Bangladeshi authorities have rejected IS' claim to that attack, saying the organisation does not exist in the country.

Siddique is the fourth professor at the university to be have been killed in recent years by suspected Islamists.

Earlier this month, a Bangladeshi law student who had expressed secular views online died when he was hacked with machetes and then shot in Dhaka.

Last year, four prominent secular bloggers were also killed with machetes.

The four bloggers had all appeared on a list of 84 "atheist bloggers" drawn up by Islamic groups in 2013 and widely circulated.

There have also been attacks on members of religious minorities including Shia, Sufi and Ahmadi Muslims, Christians and Hindus.

Muslim-majority Bangladesh is officially secular but critics say the government has failed to properly address the attacks.