NEW DELHI (AP) — Bangladesh's top court on Wednesday upheld a death sentence given to the leader of Bangladesh's largest Islamist party for atrocities and multiple killings he committed during the nation's independence war against Pakistan in 1971.

The verdict came as a wave of deadly assaults late last year on foreigners, secular writers and members of the Shiite community in the Sunni-majority nation raised international concerns that religious extremism is taking hold in the traditionally moderate country.

It is expected to aggravate the divide between moderate and extremist groups, but Prime Minister Sheikh Hasina has consolidated her position by executing the war criminals, an act previously thought almost impossible because of the complicated nature of the crimes 44 years ago. The demand for trying suspected war criminals is popular domestically despite international concern over the trial process.

Motiur Rahman Nizami, the Jamaat-e-Islami party head, was convicted last year by a special tribunal dealing with war crimes on 16 charges, including genocide, murder, torture, rape and destruction of property.

On Wednesday, a panel of senior Supreme Court judges, headed by Chief Justice Surendra Kumar Sinha, rejected Nizami's appeal, removing the last legal barrier to executing him by hanging unless he gets presidential clemency, which is unlikely.

Attorney General Mahbubey Alam expressed satisfaction with the verdict. Defense lawyers said they did not get justice.

The Jamaat-e-Islami announced a countrywide general strike for Thursday to protest the verdict, the party said in a statement.

Prime Minister Sheikh Hasina set up the special war crimes tribunal in 2010 and three senior Jamaat-e-Islami leaders and another influential member of the opposition Bangladesh Nationalist Party, headed by former Prime Minister Khaleda Zia, have already been hanged for their roles in killing people in 1971. Zia is Hasina's arch rival, and Nizami was a cabinet minister during her last term in 2001-2006.

Bangladesh says Pakistani soldiers, aided by local collaborators, killed 3 million people, raped 200,000 women and forced about 10 million people to take shelter in refugee camps across the border in India during the nine-month independence war.

The prosecution said Nizami acted as the supreme commander of the Al-Badr militia, which carried out a systematic plan to torture and execute pro-liberation supporters during the war, including teachers, engineers and journalists.

The Jamaat-e-Islami party openly campaigned against independence and its then-leader, Ghulam Azam, toured the Middle East to mobilize support for Pakistan, but the party has denied committing atrocities. Azam was sentenced for similar crimes and but died naturally in a prison hospital.

The international community has been alarmed over the deadly assaults on foreigners, secular writers and members of the Shiite community in the Sunni-majority nation.

The Islamic State group and a local affiliate have claimed responsibility for the killings of two foreigners — an Italian aid worker and a Japanese agricultural worker — as well as for attacks on the Shiites.

Bangladesh's government has repeatedly said that IS has no organizational presence in the country and accuses domestic Islamist groups along with the Bangladesh Nationalist Party and the Jamaat-e-Islami party of carrying out the attacks to destabilize the country.