Kabul: At least four persons were killed and 14 injured in a blast inside Bagram Airfield in Afghanistan's eastern province of Parwan early on Saturday, sources said.
"An explosive device detonated on Bagram Airfield resulting in multiple casualties. We will provide updates as appropriate," Xinhua news agency quoted the NATO-led Resolute Support as saying in a statement.
The Bagram Airfield, about 50 km north of Kabul, has been serving as a main US military base in Afghanistan over the past 15 years.
Earlier on Saturday, a provincial government spokesman told Xinhua that the nature of the blast was a suicide bombing.
"The initial probe found that a man disguised as a daily worker made his way to pass the first checkpoint of the base and detonated his explosive jacket inflicting casualties," spokesman Wahid Seddiqi said.
As the identities of the casualties were not immediately known, sources said the victims were local workers waiting to pass through a gate.
"Response teams at Bagram continue to treat the wounded and investigate the incident," the statement said.
Zabiullah Mujahid, a purported Taliban spokesman, claimed responsibility for the attack.
The attack was part of the insurgent's yearly rebel offensive, he said in a tweet.
Four Afghan security forces and three militants were killed and more than 130 residents wounded in a Taliban suicide truck bombing and ensuing gunfight against German Consulate office in northern Mazar-e-Sharif city on Thursday night.