A Bangladesh court on Thursday sentenced 14 people to death, including the leader of the country's largest Islamist party, over a massive arms smuggling racket ten years ago.

Motiur Rahman Nizami, 70, leader of the Jamaat-e-Islami party, was sentenced to hang after being convicted over the racket involving 10 truckloads of arms seized by police at a Bangladesh port.

"The judge sentenced 14 people including .... Motiur Rahman Nizami, to death on smuggling charges," prosecutor Kamal Uddin Ahmed told AFP from the southern port city of Chittagong.

"We're satisfied with the verdict. This is an unprecedented case and all those accused have got due justice," Ahmed said.

Prosecutors said Nizami, who was industries minister at the time, helped unload the weapons that included 4,930 sophisticated firearms, 27,020 grenades and 840 rocket launchers in April 2004.

Nizami, in custody since 2010, was among 50 people charged with smuggling and other offences over the weapons that were meant to be moved across the border to a rebel group in northeastern India.

Ex-home minister Lutfozzaman Babar and the former chiefs of the country's two main intelligence agencies were also among the 14 who were sentenced to death on Thursday over the racket.

A leader of the United Liberation Front of Asom (ULFA), Paresh Baruah, was also sentenced to death in absentia over the racket, which was meant to help the group's separatist struggle. Baruah has long been on the run.

The judge confirmed in his verdict "that the massive arms were meant to be smuggled across the border to ULFA," Ahmed said.

Security was tight in Chittagong for the judge's long-awaited verdict following a year-long trial.

Extra police and elite Rapid Action Battalion (RAB) officers were deployed in key areas as a precaution, amid concerns activists from the Jamaat-e-Islami party could take to the streets to protest the decision.

Nizami was a minister in the government of Khaleda Zia's Bangladesh Nationalist Party which was allied with Jamaat.

The parties were thrown out of power after suffering a massive defeat in December 2008 elections.

The secular Awami League-led government, which retained power after the January 5 elections, has pursued the arrests of the alleged major figures in the case since coming to power.