A helicopter carrying Turkish soldiers crashed into a house on the outskirts of Kabul, killing 16 people on Friday, according to a senior Afghan police official quoted by Reuters.

Twelve Turkish soldiers on board the helicopter and two women and two children on the ground were killed in the accident.

Twelve of our military personnel on board the helicopter have been martyred, the Turkish General Staff said in a statement obtained by Reuters. Though the exact reason for the crash isn't yet known, an Afghan police official indicated it appears to be technical failure.

A team has been sent to the crash site to investigate the cause.

The crash has escalated the uneasiness that prevails in both Afghanistan and among the NATO-led forces over the Afghanistan war. Recent incidents of civilian killings by an American soldier, Quran burning by NATO troops and protests by Afghan people has already put the NATO mission in Afghanistan in deep trouble.

Though the U.S. has reaffirmed its commitment to stick to the agreed exit plan, pressure is mounting up on the Obama administration and its partners to exit from Afghanistan at the earliest. The costly war has killed hundreds of civilians and NATO soldiers in the past year, raising concerns about prolonging the process of exit.

The recent incidents of civilian deaths had triggered violent protests across Afghanistan and a series of retaliatory attacks by militants on the troops.

Efforts by the U.S. and NATO to broker a peace agreement in the region and facilitate a phased exit received a huge blow when the Taliban announced that it was suspending negotiations with the U.S.  Afghanistan's president has also asked NATO to withdraw troops from the villages immediately.

Turkey is the only Muslim majority country in the NATO-led force and its role is limited to patrols; Turkish soldiers don't take part in combat operations.