An Afghan National Army (ANA) soldier keeps watch at the gate of a British-run military training academy Camp Qargha, in Kabul. Reuters

At least six people have been killed in a suspected suicide car bomb attack by the Afghan Taliban on an intelligence compound in the eastern city of Jalalabad.

More than 40 people, including several civilians, are reported to be injured in the dawn attack which was followed by intense gunfire.

Police have confirmed the attack but did not provide further details. The number of militant casualties is also yet to be ascertained.

"The first attacker detonated his explosives at the gate of the National Directorate of Security (NDS) office in Jalalabad city at 05:00 AM to open way for his colleague," Ahmad Zia Abdulzai, governor's spokesperson was quoted as saying.

The Taliban has claimed responsibility for the attack.

Intelligence offices and buildings of security forces are often targeted by the Taliban insurgents, who are trying to capitalise on the recent political turmoil over the election of a new president.

The Taliban-led insurgency has been posing a major challenge for Afghan security forces that are set to take over from the outgoing Nato troops.