DHAKA: Thousands of Bangladeshis poured onto the streets to applaud the execution of an Islamist party official on charges of crimes against humanity during the 1971 war, as security forces remained alert Sunday for a possible backlash from his supporters.

Know more: Bangladesh hangs Jamaat-e-Islami leader for 1971 war massacre

Mohammad Kamaruzzaman was hanged Saturday night in Dhaka’s central jail, a senior prison official, Forman Ali, told reporters. He was buried early Sunday amid tight security, according to his brother, Kafil Uddin.

Prosecutors said Kamaruzzaman, an assistant secretary general of the Jamaat-e-Islami party, headed a militia group in central Bangladesh in 1971, and was behind the killings of at least 120 unarmed farmers. Bangladesh blames Pakistani soldiers and local collaborators for the deaths of three million people during the nine-month war following which it separated from Pakistan.

Jamaat-e-Islami denounced Kamaruzzaman’s execution and called for a nationwide general strike Monday. At the same time, thousands of people applauded the execution on the streets of Dhaka and other cities, a sign of popular approval of the war-crime trials launched by Prime Minister Sheikh Hasina.

More rallies supporting the execution were planned for Sunday.

“We are happy that justice has been delivered finally,” said Mohammad Al Masum, a student at Dhaka University, who joined a procession in Shabagh Square.

“I did not see the war but I am sure the families that lost their dear ones will be happy today. “

Premier Hasina has vowed to continue the trials despite pressure from abroad and the opposition at home.

Jamaat-e-Islami, which garners about 2 percent to 3 percent of popular vote in Bangladesh, has been weakened significantly with most of its senior leaders having been convicted.

Another assistant secretary of the party, Abdul Quader Mollah, was executed in 2013 for similar crimes.

The U.N. High Commissioner for Human Rights Ravina Shamdasani, earlier this week, urged Bangladesh not to carry out the execution, saying that Kamaruzzaman's trial did not meet international standards.

The United States was more guarded in its assessment of the trial, but still urged the government not to proceed with the capital punishment.

“We have seen progress, but still believe that further improvements ... could ensure these proceedings meet domestic and international obligations,” State Department spokeswoman Marie Harf said in a statement shortly before the execution.

But the Bangladeshi government asserts the trial met all proper standards, with the defendant being given the opportunity to challenge the prosecution's case in open court and appeal the verdict all the way up to the Supreme Court.

Kamaruzzaman, however, refused to seek presidential clemency.

The initial trials that followed Bangladesh's creation four decades ago were halted after the assassination of the then president and independence leader Sheikh Mujibur Rahman (Hasina's father) and most of his family members in a 1975 military coup.

Hasina revived the process, making good on a pledge she made before 2008 elections.