A blast hit Jalalabad city, the capital of Afghanistan's eastern Nangarhar province on Saturday, injuring at least six people, a local TV channel reported.

"The explosion targeted a vehicle of National Security Directorate (NSD) ," the private Tolo television channel quoted Ahmad Zia Abdulzai, spokesman for the provincial administration, as saying.

The NSD is an intelligence service of the country.

The blast occurred in the fourth precinct of Jalalabad smashed windowpanes of several buildings, the TV channel reported.

However, Abdulzai failed to disclose whether it was a suicide attack or a roadside bombing.

Earlier health officials at Jalalabad Hospital said that they have received six injured people and most of them are in stable conditions. No group or individual has so far claimed the responsibility for the incident. Nangarhar, regarded as a peaceful province in eastern Afghanistan, has been the scene of explosions this month as another explosion targeting a NATO-led International Security Assistance Force in Jalalabad city on April 7 injured 10 people, all of whom civilians.