Bangladeshis on Sunday paid tribute to an American critic of religious extremism killed in Dhaka, the latest in a series of attacks on writers who support free thinking values in the Muslim-majority nation.

Avijit Roy, a U.S. citizen of Bangladeshi origin, was hacked to death by machete-wielding assailants on Thursday after a book fair, sparking widespread condemnation from home and abroad.

His wife and fellow blogger Rafida Ahmed suffered head injuries and lost a finger and remains in hospital in a serious condition.