President Md Abdul Hamid rejected their mercy petitions, Home Minister Asaduzzaman Khan Kamal told bdnews24.com after 10pm on Saturday.
Bangladesh waited for the execution throughout the day but there was no sign until evening.
A top jail official told bdnews24.com that the authorities did not get any decision before the evening.
“But we are prepared. The rush started in the evening,” he said.
The activities in and around the jail gained pace when Additional Inspector General of Prisons Col Fazlul Kabir entered the jail just before 8pm.
The authorities then called the families of BNP leader Salauddin Quader and Jamaat-e-Islami Secretary General Mujahid.
The families entered the prison after 9:30pm.
The high power lights were lit in the evening. The prison guards rushed to and fro.
IG Prisons Brig Gen Syed Iftekhar Uddin and Dhaka’s deputy commissioner entered the jail at around10:15pm, followed by Civil Surgeon Abdul Malek Mridha.
Deployment of police and RAB personnel had been increased since Saturday morning, and was propped up manyfold in the afternoon.
Until 4pm, only RAB personnel had been deployed in front of the prison at Old Dhaka’s Najimuddin Road, but later armed police were also stationed in the area.
A jail official said the authorities checked the execution tools, including the gallows, earlier in the day.
Four executioners were ready, he said.
The jail Imam was asked to administer the confession, he added.