At least nine people have been killed and over 30 wounded after unknown gunmen attacked Jalalabad's customs finance department on Sunday afternoon, local officials said.

According to them clashes are ongoing, local officials confirmed.

Nine people have been killed and 30 others were wounded in the attack, provincial governor spokesman Attaullah Khogyani said.

The attack happened in Jalalabad city after a suicide bomber detonated his explosives close to the gate of the finance department. Other insurgents then stormed the building, said officials.

No further details have yet been provided.

However, an eyewitness said four explosions had been heard in the area.

No group including the Taliban immediately claimed responsibility for the attack.