Over 100 small explosives have been reported detonated across Bangladesh, Channel News Asia is reporting.:

A total of 111 explosions occurred near bus and train stations, courts and administrative buildings, various police officials said, adding they appear to have been caused by small, homemade devices.
Police in some affected cities said leaflets - apparently from a recently banned Islamic extremist group calling for the implementation of Islamic law - were found near the scene of the blasts.
Some were written in Arabic and others in Bangla.
"There are bomb blasts all over the country. We have reports of some injuries but no fatalities yet," said Abdul Kaiyum, Bangladesh’s Inspector General of Police.
In addition to Dhaka and Chittagong, police reported nine explosions in the southern town of Barisal and at least six in the southwestern town of Khulna.
Police chiefs in 11 other towns and districts reported a further 61 blasts.

The report does not mention any casualties.

UPDATE: Rezwan has more.