A suicide bomber targeted the National Directorate of Security (NDS) building in Turkham port of Nangarhar province early on Sunday morning, wounding three NDS soldiers.

Noor Akbar, the Torkham police chief, said a suicide bomber carrying explosives around 7:00am local time first entered the NDS building and shot one NDS solider and then detonated himself inside. 

"The solider that was shot by the suicide bomber is in a bad condition and was taken to the hospital, the two other wounded soldiers are in good condition," Akbar told TOLOnews.

No one has claimed responsibility for the attack yet.

The blast comes after a suicide bomber detonated an explosives-laden vehicle near a NATO military convoy entering Kabul International Airport early Wednesday, killing himself but causing no other casualties.

Torkham is one of the major border crossings between Afghanistan and Pakistan, located on the Durand Line border. It connects Nangarhar province of Afghanistan with Pakistan's Federally Administered Tribal Areas (FATA) and Khyber Pakhtunkhwa.