The explosion took place in the central hall of the mosque on Monday at around 1 pm.
India extended condolences to the families of the victims of the deadly terror attack that shook Peshawar in Pakistan yesterday.
So far, the toll of the dead stands at 90 with over 100 people injured, Geo News reported citing Radio Pakistan.
Taking to Twitter, MEA Spokesperson Arindam Bagchi wrote, "India extends its deep condolences to the families of the victims of the terror attack in Peshawar yesterday. We strongly condemn this attack, which has taken the lives of so many people."
The explosion took place in the central hall of the mosque on Monday at around 1 pm after a suicide bomber blew himself up. A rescue operation is being carried out to pull out bodies from the debris of the mosque, Geo News reported citing an official.
According to security officials, the suicide attacker was present in the front row during the prayers when he blew himself up. The outlawed Tehreek-e-Taliban Pakistan (TTP) has claimed responsibility for the attack.
Speaking to Geo News, Capital City Police Officer (CCPO) Peshawar Mohammad Aijaz Khan said that the explosion appears to be a suicide attack and the head of the suspected bomber has also been found at the site.
"It is possible that the attacker was already present in the Police Lines before the blast and that he may have used an official vehicle [to enter]," Geo News quoted Mohammad Aijaz Khan as saying.
"About 1,500 to 2,000 police officers visit the Police Lines daily," he added.
Earlier, an eyewitness said there were at least 120 people at the mosque when the explosion took place. He said that the injured mostly included police personnel.
Khyber Pakhtunkhwa Caretaker Chief Minister Muhammad Azam Khan announced a day of mourning in the province on Tuesday after the attack, according to a Geo News report. He said that the national flag will be at half-mast in the province.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)