Security officials said two vehicles, a truck and a Humvee, were used in the suicide bombing targeting Paktia police training college.
Paktia Police Chief Killed In Deadly Twin Bombing
Security officials have confirmed that Toryalai Abdyani, the police chief for Paktia province, was killed in Tuesday morning's deadly suicide bombing in Gardez City.
In addition, the deputy governor Abdul Wali Sahee, said more than 20 people have been killed and over 70 wounded. However, other sources said the casualty toll, including dead and wounded, was over 150.
The incident started shortly after 9.30 am local time and ended at about 1:30pm, according to the Ministry of Interior.
Security officials said two vehicles were used in the attack - one truck bomb and one Humvee 'bomb'. The target was the police training college.
Following the explosions, insurgents stormed the center and by early afternoon clashes were still ongoing.
The number of attackers is unknown.
TOLOnews journalist Abdulhaq Omeri, reporting from the scene, said that the Police Special Forces Units and Commandos led the operation.
Officials said both police personnel and civilians are among the victims. They said dozens of civilians were at the center to collect passports and other documents.
Extensive damage was also done to the buildings in the surrounding area, Omeri reports.
The Taliban has claimed responsibility for the attack.