Kabul (AFP) - A US F-16 was struck by enemy fire in eastern Afghanistan, military officials have confirmed to AFP, in a rare instance of an advanced fighter jet coming under a Taliban-claimed attack.

The multi-million dollar jet sustained significant damage, forcing it to jettison its fuel tanks and munitions before returning to base, officials said.

The attack occurred last Tuesday in the Sayid Karam district of eastern Paktia province, much of which is under control of the Taliban, who have been waging an insurgency against US-led NATO forces and government troops since they were forced from power in 2001.

The militant group claimed they had downed the jet in a statement posted on Twitter that evening, but when contacted for comment, the US military initially said it had no "operational reporting to support the Taliban claims".

Photographs of the site obtained by AFP and seen by J. Chacko, an open-source military analyst based in London, indicated the jet had lost two "drop-tanks" -- fuel tanks used to extend flight time -- an air-to-ground missile, and two other unguided bombs.

They also show masked militants posing with the hardware.

When presented with the images, the US military confirmed in a statement to AFP late Saturday: "On October 13, a US F-16 encountered small arms fire in the Paktia Province in Afghanistan. The surface to air fire impacted one of the aircraft's stabilisers and caused damage to one of the munitions.

"The pilot jettisoned two fuel tanks and three munitions before safely returning to base. The pilot received no injuries and safely returned to base."

The Taliban have shot down several military helicopters using small-arms fire, but never an F-16 -- an advanced jet capable of supersonic speeds and reaching heights of 50,000 feet, which have been deployed in Afghanistan since the beginning of the US-led military in 2001.

Since the 2014 drawdown, the US Air Force has maintained one squadron of F-16s at Bagram Air Base.

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In April 2013, a US F-16 crashed into a mountain near Bagram while flying low in bad weather, according to a US military investigation, and a Dutch pilot was killed when his F-16 crashed in 2006.

The latest generation of the F-16 has a price tag of more than $100 million per jet according to a deal reached with the Iraqi Air Force last year, which included spare parts and a support package.

- Special forces air support? -

Tuesday's incident underscores the risks foreign forces still face at the hands of the group as Washington extends its military presence in the country beyond 2016.

Chacko, as well as two other military analysts contacted by AFP, said the jet would have had to be flying very close to the ground to be struck by Taliban fire -- perhaps as low as a few hundred feet.

"An F-16 would have to be flying very low altitude at close to minimum speed for it to receive actionable fire from small arms," an ex-military source said.

"Small arms fire could reach a maxium height of around 1,500 metres (5,000 feet)," a third analyst said.

Niaz Mohammad Khalil, district governor of Sayid Karam, told AFP that neither US nor Afghan forces had been conducting any operation in the area that would have necessitated the use of air cover at the time of the attack.

"We had no operation at the time of (the) crash, but the jet was flying very low... There were also other jets flying over the area," he said.

According to Chacko, the fact that local officials did not mention any friendly forces in the area meant the pilot was likely providing covering fire for a Special Operations Forces (SOF) team that ran into trouble.

The US military declined to comment on the pilot's mission.

The US military acknowledges that remaining SOF teams are still conducting on the ground missions against the Taliban and Al-Qaeda, although NATO forces officially ended their combat mission in Afghanistan at the end of 2014.