At least 23 people were killed and over 80 others injured as a massive suicide bomb blast ripped through a police residential area Tuesday night in the city of Kohat in Pakistan's northwest province of Khyber Pakhtunkwa.

Dozens of people are still trapped under the rubble of the damaged buildings after an estimated 400 kilograms of explosives were detonated, said local police officers.

According to Xinhua reporter and the local media reports, an unidentified suicide bomber rammed an explosive-laden rickshaw at one of the buildings inside a police residential area, destroying at least 25 living quarters and damaging many buildings including a nearby local TV station.

Police have cordoned off the blast area and rescue team has arrived at the scene shortly after the blast, said an eyewitness.

All the injured people are police and their family members including many women and kids, hospital sources said adding at least five of the injured are in critical condition.

No group has claimed responsibility for the blast yet.

This is the fourth deadly suicide bomb blast in Pakistan this month.

Early on Monday morning, a suicide bomber drove an explosive- laden car into a police station in the city of Lakki Marwat in Pakistan's northwest province of Khyber Pakhtunkhwa, killing 19 and wounding more than 40 others. No group has claimed responbility for the attack.

On September 1, at least two suicide bomb explosions hit a Shia Muslim procession in Pakistan's eastern city of Lahore, killing 37 people and injuring more than 200 others.

On September 3, a suicide bomber attacked a rally in the country's southwestern city of Quetta, leaving 70 people dead and more than 160 others injured.

A Punjab-based extremist Sunni group named Lashkar-e-Jhangvi has claimed responsibility for both of the afore-said suicide attacks.