DHAKA: A Bangladeshi court sentenced a senior Islamist opposition official to life in prison Tuesday for mass murder and crimes against humanity during the 1971 liberation war against Pakistan.

Abdul Quader Molla, 64, the fourth highest ranked leader of the Jamaat-e-Islami party, is the first politician to be found guilty by the International Crimes Tribunal, a much-criticised domestic court based in Dhaka.

Molla cried "Allahu Akbar" (God is greater) and said all the charges were false after the presiding judge Obaidul Hassan delivered the verdict in a crowded court, blanketed with heavy security.

The judgement sparked protests by Jamaat, the country's largest Islamic party which enforced a nationwide strike Tuesday in anticipation of the conviction. It warned it would resist "at any cost a government blueprint" to execute its leaders.

"He deserved death sentence because of the gravity of the crimes. But the judge gave him life imprisonment," Attorney General Mahbubey Alam said, adding Molla "had directly participated" in the killing of more than 350 people near Dhaka.

The verdict is the second to have been handed down by the tribunal. On January 21 a top TV preacher, an ex-Jamaat official, was sentenced to death in absentia for murder and genocide.

The judge in Molla's case refused a prosecution bid to try him for genocide.

Molla's lawyer Nazim Momen said they would appeal the verdict as it was "politically motivated".

Ten other opposition figures -- including the entire leadership of Jamaat and two from the main opposition Bangladesh Nationalist Party (BNP) -- stand accused of war crimes.

Both Jamaat and BNP have labelled the cases "show trials" aimed at barring the leaders from upcoming polls. International rights groups have questioned the proceedings.