“In his initial confessions, he said that he was strongly motivated to kill the soldiers when he saw the video of a foreign soldiers urinating on Afghan corpses,” the intelligence source said.

French Defence Minister Gerard Longuet said during a visit to Kabul at the weekend that he had been told the soldier who killed the four soldiers and wounded 15 others was a Taliban infiltrator.

But President Hamid Karzai did not make the same accusation in a statement Sunday, describing the attack as “an isolated and individual action”.