Dhaka (CNN) -- Protests have erupted across Bangladesh after a tribunal sentenced a former Islamic party leader to 90 years in jail for war crimes.
The three-member tribunal found 91-year-old Ghulam Azam guilty on all counts -- murder, conspiracy, planning, incitement and abetting related to mass killings and rapes in 1971 during the country's war of independence.
The conviction sparked angry scenes across the country, both from his supporters, who want his release, and opponents, who found the punishment too lenient.
The government beefed up security deploying huge contingents of paramilitary forces and anti-riot police across the country.
Jamaat-e-Islami, the party that Azam led for 31 years, called for a general strike demanding his release.
The judge presiding over the tribunal, Justice A T M Fazle Kabir, said that Azam will "serve the sentence consecutively or till his death."
According to government records, three million people were killed and thousands of women were raped during the nine-month conflict when Bangladesh, formerly known as East Pakistan, seceded from its union with West Pakistan.
Azam was arrested in January this year and has been detained in a prison cell at the Bangabandhu Sheikh Mujib Medical University Hospital in Dhaka, officials said.
Azam, who headed the party from 1969 to 2000 and opposed the birth of Bangladesh in 1971, was present in court but didn't make any comment on Monday. He had earlier denied the charges.
It was the fifth judgment by the tribunal, which has handed down the death penalty or life imprisonment to four other party leaders. Jamaat-e-Islami opposed Bangladesh's independence and helped the Pakistani army in East Pakistan.
The war crimes tribunal was launched by Prime Minister Sheikh Hasina in 2010.
Jamaat-e-Islami is the largest Islamic party in Bangladesh and has formed an alliance with opposition parties.