Police said they were arrested from the Islamic International School and College in Dhaka's Badda locality, bdnews24 reported.
Nizami was hanged on May 11 this year for war crimes including mass murder, rapes, violence etc. He was the third minister to be executed for war crimes.
He was the chief of Jamaat party which actively opposed Bangladesh's liberation from Pakistan during nine months long war in 1971.
"A raid was conducted on a tip-off of a secret meeting of Jamaat leaders and activists," a police official said.
Those arrested included the party's Badda unit chief Fakhruddin Kefayatullah.
Nizami's wife, Shamsun Nahar Nizami, who is the principal of the school, was not arrested as she was not present in the school during the raid.
The police have not clarify the charges against those arrested.
Jamaat activists have been named in several cases of violence ahead of the 2014 national polls.
Many of the suspected Islamist militants who were involved in recent targeted killings and terror attacks, were found to be from the party's student wing Islami Chhatra Shibir.
