Several bombs exploded outside a court in the port city of Chittagong and almost simultaneously a bomb exploded at a court library in Gazipur town, 30 kilometers north of the capital Dhaka.

Police suspect suicide bombers carried out the attacks. They have stepped up security across the country.

Policemen and lawyers were among those injured in the blasts, the latest in a series of bombings that have targeted judges, journalists, and politicians in recent months.

Hundreds of lawyers boycotted court proceedings and staged street protests across the country demanding the government act to prevent further attacks.

Bangladeshi police believe the courts are being targeted because they symbolize the secular laws that Islamic groups, such as the banned Jamaat-ul-Mujahedin, want to replace with strict Islamic laws.

"This may be a strategy of the Islamic militants because what they say we want to establish in Bangladesh is the rule of Allah, and they have decided to set an example by demolishing the courts, that man-made laws will not be allowed to function," says Ataus Samad, an independent political analyst in Dhaka.

Just two weeks ago, a suspected suicide attacker killed two judges and police say other members of the legal profession have received death threats from Islamic militant groups.

And across Bangladesh, hundreds of small bombs exploded outside government buildings and courts in August and October.

Most of the previous attacks have been blamed on Jamaat-ul Mujahedin.

The government says it is determined to crush the militants but the opposition and political analysts say the authorities are not doing enough to crack down on the Islamic fundamentalists.

"The forces which were seen to be responsible for the last bomb blasts have not been contained at all, and the government has not shown the serious resolve to deal with these forces. Therefore, I think this is a tendency which will continue," says Sukh Deo Muni, a New Delhi academic specializing in South Asian affairs.

Dhaka police said Monday that security at embassies had been tightened after bomb threats aimed at the U.S. and British diplomatic missions.