Dhaka, Bangladesh: A Bangladesh court Monday sentenced 26 people to death after hearing how a politician from the ruling Awami League hired members of the country's elite security unit to assassinate political rivals.

At the end of a trial that gripped the nation, a judge found all 35 defendants in the case guilty of involvement in the abduction and murder of seven people in the central city of Narayanganj in April 2014.

Convictions of security force members are rare in Bangladesh. Rights activists say they frequently carry out unlawful killings and are effectively able to operate in a climate of impunity.

Judge Syed Enayet Hossain ordered 26 of the defendants to hang after the year-long trial in Narayanganj, while the other nine were handed prison sentences ranging from seven to 17 years.

"Of the 26 who have been sentenced to hang, 16 were the members of the Rapid Action Battalion (RAB)," prosecutor S.M. Wazed Ali told AFP. 

Twenty-three of those convicted were present in the crowded court when the verdict was announced but the other 12 are still at large.

The bodies of the victims were found floating in a river, three days after witnesses reported seeing a group of people being bundled into the back of an unmarked van outside the city's international cricket stadium.

Among those sentenced to death was Tarek Sayeed, a commander in the Rapid Action Battalion (RAB) who is the son-in-law of a minister in Prime Minister Sheikh Hasina's cabinet.

Prosecutors described during the trial how Nur Hossain, a local councillor in Narayanganj and at the time a member of Hasina's Awami League, hired RAB officers to kill his arch-rival Nazrul Islam and four of his aides.

- Bodies dumped -

A lawyer who filmed the abductions outside the stadium on his mobile phone was then himself kidnapped, along with his driver. 

All seven of the victims were killed and had their bellies cut before their bodies were dumped in the Shitalakshya river outside the city.

Hossain, who was among those sentenced to death on Monday, fled to neighbouring India after the killings but was later arrested in Kolkata and extradited.

"We're satisfied. We finally got justice," Shakhawat Hossain Khan, a lawyer for the plaintiffs, told reporters outside the courtroom which was guarded by hundreds of police on Monday morning.

He said the prosecution faced difficulties in bringing the RAB officers to trial and pointed out that they had only been detained after the Bangladeshi high court intervened and ordered their arrest. 

Opposition parties say hundreds of their activists have been abducted during Hasina's eight years in power and never seen again, although the government denies any involvement by the security forces.

Local rights groups say at least 326 people have disappeared since January 2009, many of whom were members or supporters of opposition parties.

"Today's verdict will to some extent change public perception that influential people and members of the security forces are above law," said Nur Khan Liton, acting head of the group Ain o Salish Kendra.

"But hundreds of people still remain traceless and in many cases allegedly abducted by the security forces. The government should also investigate every one of these abductions," he said.