A special Bangladeshi court on Monday sentenced a 90-year-old top Islamist to 90 years in prison for masterminding atrocities during the 1971 war of independence against Pakistan.

Ghulam Azam, compared by prosecutors to Nazi leader Adolf Hitler, was found guilty of five charges of planning, conspiracy, incitement, complicity, and murder during the war, which the government says killed three million people.

However, Azam, the wartime head of the country’s largest Islamic party, Jamaat-e-Islami, and now its spiritual leader, was spared the death penalty because of his age and health, and was instead sentenced to nine decades in prison, a top government lawyer said.

“He was found guilty beyond reasonable doubt in all five charges and jailed (for) 90 years. The tribunal observed that he deserved (the) death penalty,” junior attorney general M.K. Rahman said.

“Some kind of justice is done but we are not happy,” Rahman added.

Azam, the fifth person convicted by the controversial International Crimes Tribunal, remained stoney-faced in his wheelchair as the sentence was read out.

Violence erupted in cities across Bangladesh ahead of the judgement, killing two people, as supporters of Azam clashed with police and paramilitary troops who responded with rubber bullets and in some cases live rounds, officials said.

Jamaat, the country’s largest Islamic party and a key member of the opposition, had called a nationwide strike to protest the verdict, saying the war crimes trials are aimed at eliminating its leaders.

Announcing the verdict, the tribunal said Azam held “superior responsibility” for the atrocities committed by militias, that he helped to create to support the Pakistani Army during the war.

“It has been proved that Ghulam Azam was the architect of the militia groups including Peace Committee, al Badr, Rajakar,” judge A.T.M. Fazle Kabir told the packed tribunal.

Prosecutors had sought the death penalty for Azam, describing him as a “lighthouse” who guided all war criminals, and the “architect” of the militias.

When India intervened at the end of the nine-month war and it became clear Pakistan was losing, the militias killed dozens of professors, playwrights, filmmakers, doctors and journalists.

Azam was described as the “mastermind” of the massacres of the intellectuals. Many of their bodies were found a few days after the war at a marsh outside the capital, blindfolded and with their hands tied behind their backs.

Azam’s lawyer Tajul Islam pledged to appeal, saying the charges were based on newspaper reports of speeches Azam gave during the war, which led to the creation of Bangladesh.

“We’ll definitely appeal. The evidence presented by the prosecution miserably failed to prove him guilty. It’s a perverse judgement,” Islam told AFP.

Ahead of the verdict, one person was killed in the northwestern town of Shibganj, after paramilitary troops fired at Jamaat activists hurling homemade bombs, local police chiefs told AFP.

A low-level official from the ruling party was also beaten to death by suspected Jamaat supporters in a southwestern district of the country, the police chiefs also said.

Police fired rubber bullets at protesters in the capital and the cities of Bogra, Comilla and Rajshahi after activists went on the rampage, attacking and torching dozens of vehicles, police officials told AFP.

In the capital, several thousand secular protesters gathered to reject the verdict as too lenient. “If he doesn’t deserve death, who does?” said student activist Lukcy Akter in a central Dhaka square.

Previous verdicts by the tribunal have sparked widespread and deadly violence on the streets of a country that has a 90 per cent Muslim population.

Three of the five Islamists convicted by the tribunal have been sentenced to death, and one was given life imprisonment.

The opposition has criticised the cases as politically motivated and aimed at settling old scores rather than meting out justice.

Unlike other war crimes courts, the Bangladesh tribunal is not endorsed by the United Nations. The New York-based Human Rights Watch group has said its procedures fall short of international standards.

The government maintains the trials are needed to heal the wounds of the 1971 war in which it says three million died. Independent estimates put the death toll at between 3,00,000 and 5,00,000.