Pakistan suicide bombing death toll climbs to 100
"At least 89 people lost their lives," Ayaz Khan, a spokesperson for the local police, told the Deutsche Presse-Agentur (dpa).
Some 221 people were wounded in Monday's suicide bombing in a crowded mosque located inside a high-security zone next to a police headquarters.
At least 10 of the wounded were in critical condition, a hospital spokesperson said.
Overnight, at least 10 bodies were recovered from the rubble of the mosque's collapsed wall and roof.
"Majority of the victims, including clerical staff, were from the police," Khan said.
The attack was one of the country's deadliest in years and struck during afternoon prayers.
An inquiry has been launched into how the multi-layered security infrastructure at the site was breached.
"It was no less than an attack on Pakistan," Prime Minister Shehbaz Sharif said.
No group has yet claimed responsibility for the attack in Peshawar, located near the border with Afghanistan, amid a surge in violence and a worsening security situation in Pakistan.
Both the Pakistani Taliban and the Daesh terrorist group have targeted worshippers at mosques in the past.
The violence has surged after months of peace talks between Islamabad and the Taliban militants hiding in Afghanistan collapsed in November.
Last month, a car bomb killed one police officer in Islamabad.