A university professor has been hacked to death in Bangladesh, in an attack police say is similar to killings of secular bloggers and atheists by suspected Islamist extremists.

AFM Rezaul Karim Siddique, 58, was a professor of English at Rajshahi University in the country's north-west.

He was attacked with machetes by unidentified assailants while on his way to the university from his home.

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