Security has been stepped up across Bangladesh after scores of small explosions ripped through towns and cities in the country, killing two people and injuring at least 100. No one has claimed responsibility for the blasts, but police say they appear to be the handiwork of a banned Islamic group. Several people have been arrested in connection with the blasts.

Police say the bombs exploded almost simultaneously near bus and train stations, courts and government buildings, airports, and markets across the country.

More than a dozen explosions occurred in the capital Dhaka and several others in the country's second largest city, Chittagong.

Police say they were small devices and generally did not cause much damage. Nevertheless the blasts triggered panic and massive traffic jams as people fled or rushed to schools to collect children.

At least one official has told journalists that the blasts appeared to be an "organized attack."

Leaflets found at some of the blast locations carried a call by the banned group, Jamaat-ul-Mujahideen, for Islamic rule in Bangladesh.

The group, along with another hard-line organization, was banned in February for alleged links to a series of killings and bomb attacks on a variety of targets last year - cinemas, religious places, and opposition meetings. The groups denied involvement in the violence.

An independent political analyst in Bangladesh, Ataus Samad, says suspicion is falling on Islamic militant groups. He says the government has been criticized for not cracking down hard enough on their activities.