The local administration beefed up security ahead of Wednesday's verdict to avoid untoward incidents.
Seven BGB and RAB platoons were patrolling the district along with police, who had also been deployed at key points, said Additional Superintendent of Police Siddiqur Rahman.
Jamaat chief Nizami, who led the notorious Al-Badr militia during the Liberation War, was sentenced to death on Wednesday by a special tribunal.
An elated Tofazzal Hossain Master, who testified against Nizami, said he was happy with the verdict.
"I now demand swift execution of the sentence," he said.
Pabna Muktijoddha Sangsad's Deputy Commander Abdul Baten, too, was happy with the verdict, though it came after a long wait and demanded quick execution of the sentence.
Santhia Upazila freedom fighter commander Abdul Latif was of the same view.
But the Jamaat and its students front Islami Chhatra Shibir rejected the sentence.
Jamaat alleged the government was using the war crimes tribunal as a political tool to eliminate its top brasses, an accusation the government denies.
Jamaat-Shibir activists tried to take out a march in the afternoon but police quickly intervened and dispersed them.
Santhia police OC Shahid Mahmud Khan said they had taken additional safety measures for the witnesses in the Nizami case.