DHAKA (Reuters) - Gunmen opened fire and tossed bombs on Sunday at a prison van carrying militants of a banned Islamist movement to a court house, freeing three of their colleagues and killing a policeman in the ambush, police and witnesses said.
The three convicts sprung from their police escort were members of the group Jamaat-ul-Mujahideen Bangladesh (JMB), including the group's explosives expert. Two had been sentenced to death.
The group was highly active around 2005, when it was involved in spate of bombings on judicial personnel, courts and other targets, but has been relatively quiet over the past 10 years.
Police Inspector General Hassan Mahmood Khandker said the incident showed the militants had not been rooted out entirely. "It is a clear indication that they are still active," he told reporters.
He said the attack was the first such ambush on a prison van.
The militants had been on their way to a court in Mymenshing to testify in another trial, said Abdur Razzak, superintendent of Kashimpur jail, where all three had been held.
Militants blocked a highway in Mymenshing, 120 km (75 miles) north of Dhaka, with two cars and set off several bombs to halt the prison van, police said. One policeman died on the spot and three were injured.
About 20 masked men then jumped out from a microbus and opened fire on the van, Subedar Habib, who was injured in the attack, told reporters in hospital.
Police who mounted a manhunt and searched districts near the incident later detained one of the men. They also offered a reward of 200,000 taka ($2,560) for help in capturing them.
Border patrols had been put on alert to stop the men fleeing the country, junior law minister Asaduzzaman Khan Kamal said.
Six leaders of the Islamist militant group were hanged after being convicted of killing two judges in 2005. Among them was JMB chief Shaikh Abdur Rahman, a veteran of conflicts in Afghanistan.
The group exploded nearly 500 bombs almost simultaneously on August 17, 2005, across Bangladesh, including the capital Dhaka, in attacks largely aimed at frightening authorities.
Its militants later carried out suicide attacks on various courthouses, killing 25 people, including judges, lawyers and policemen, and injuring hundreds.