The NATO-led coalition in Afghanistan said on Tuesday there were no signs of organised infiltration of the Afghan security forces by insurgents, and it was too early to say if the Taliban were behind last week's killing of four French soldiers.
Investigations of past rogue attacks had uncovered many reasons for so called green-on-blue shootings, where Afghan police and soldiers turned weapons on their Western allies and mentors, a spokesman for the International Security Assistance Force (ISAF) coalition said.
There are no indicators of a systemic infiltration into the Afghan National Security Forces. Actually, this is something that we very carefully look at on a daily basis, ISAF spokesman Brigadier General Carsten Jacobsen told reporters.
The Afghan Taliban said on Saturday it had recruited an Afghan National Army soldier to shoot the French soldiers in eastern Kapisa province a day earlier.
The attack prompted France -- the fifth biggest troop contributing nation -- to suspend all military operations in Afghanistan and to threaten an early exit from the NATO-led war there.
French Defence Minister Gerard Longuet was also quoted as saying the shooter was an insurgent infiltrator, but ISAF said Longuet's comments had been not quite as suggested.
It is far too early to make a statement of Taliban involvement in general, or in this specific incident, at the present time, Jacobsen said.
The shootings last week were the latest in a series of attacks by Afghan security forces against their Western allies. One of the worst occurred in April last year when nine Americans were shot dead by a veteran Afghan air force pilot in Kabul.
Green-on-blue shootings allude to the colours of the Afghan army and the blue NATO symbol, although the coalition no longer releases the number of its soldiers killed by Afghans.
ATTACKS ON THE RISE
Such attacks have been rising since an Afghan police officer shot dead five British soldiers in Helmand province in 2009.
Two members of the French Foreign Legion and one American soldier were also killed in separate episodes in December.
France's Longuet flew to Kabul at the weekend for emergency talks with the government and to seek guarantees on the safety of the near-4,000 French troops in the country, based mainly in mountainous Kapisa.
France said on Tuesday it would wait until the visit of Afghan President Hamid Karzai to Paris on Friday to decide whether to speed up the withdrawal.
Jacobsen said ISAF was committed to reaching its goal of a full handover to Afghan security forces ahead of the withdrawal of foreign combat troops in 2014. Investigations into the French shootings, he said, were still underway.
But he also held open the door to a possible tightening of the vetting procedure to ensure Afghan police and soldiers held no secret insurgent sympathies and he acknowledged the West was struggling to reach its target of a 352,000-strong Afghan security force.
The vetting process has been around a long time. We are confident it is good, but we will look at it carefully. This process minimises the chance of Taliban infiltration (but) does not completely mitigate individual failures, he said.
(Additional reporting by Amie Ferris-Rotman; Editing by Ron Popeski)