An Afghan soldier has been sentenced to death for killing five French soldiers in a "green-on-blue" attack in Kapisa province in January, the defence ministry said Tuesday.

The incident, in which the soldier turned his gun on his French colleagues, prompted France to speed up its planned withdrawal of troops from NATO operations in Afghanistan.

The man, Abdul Sabor, was sentenced to death by hanging in a military court in Pul-i-Chakri prison on Monday, a defence ministry source said.

"Yes, I can confirm it. His name is Sabor," said Mohammad Zahir Azimi, a ministry spokesman.

Four unarmed French soldiers were killed outright and 15 others were wounded as they jogged on their military base on 20 January. A fifth French soldier died weeks later from his wounds.

The shooting underscored the difficulties facing NATO troops as they work alongside and train Afghan forces ahead of their planned withdrawal from the war-torn country by the end of 20124.

The number of so-called green-on-blue attacks—in which Afghan forces turn their weapons against their Western allies—has escalated this year.

In the latest incident, three British soldiers were shot dead by a man in an Afghan police uniform in the southern province of Helmand earlier this month.

Their deaths took the green-on-blue toll this year to at least 26, in 18 such incidents.

Although Taliban insurgents claim some of the attacks, many are believed to be the result of cultural differences and antagonisms between Afghan soldiers and their Western counterparts.

It was not immediately clear whether the military court had established the motive behind Sabor's killing of the French soldiers.

He reportedly told security officials after his arrest that he acted in retaliation after a video came to light of US Marines urinating on the corpses of dead Afghans.

Earlier this month, French troops handed over the key Afghan province of Kapisa to local forces, completing an important stage in the accelerated withdrawal from the war-torn country.

France is the fifth largest contributor to NATO's International Security Assistance Force (ISAF), which is due to pull out the vast majority of its 130,000 troops by the end of 2014.

Kapisa was the last area of Afghanistan under the control of French soldiers, the bulk of who are due to leave by the end of 2012, two years earlier than most NATO troops.

While capital punishment is allowed under Afghanistan's constitution, President Hamid Karzai has said he is reluctant to sign death warrants, and hundreds of prisoners sentenced to death are believed to remain in prison.

The latest publicly-known execution in Afghanistan was of two men in June 2011 for a suicide attack on a bank in Jalalabad in which 38 people were killed.

In October 2007, Afghanistan announced it had put to death 15 men, one convicted of killing three foreign journalists, in only the second confirmed executions since the fall of the Taliban regime in 2001.