By Ibon Villelabeitia
ANKARA (Reuters) - Turkish rights groups called on Friday for a U.N.-sponsored investigation after Turkish warplanes killed 35 villagers in an airstrike targeting Kurdish rebels on the Iraqi border that the government has called an operational mistake.
The incident, which is under government investigation, has raised tensions with minority Kurds in Turkey, sparking clashes between stone-throwing protesters and police in cities in the restive mainly pro-Kurdish southeast and areas in Istanbul.
The attack, one of the largest single-day civilian death tolls since the militants launched their armed insurgency in 1984, came at a time when Prime Minister Tayyip Erdogan has been trying to engage Kurds in talks to write a new constitution expected to address long-held Kurdish grievances.
"The incident requires a more detailed investigation, but it is an execution without due process, and carries the characteristics of a mass murder in terms of the number of victims," human rights groups IHD and Mazlumder said in a preliminary report into Wednesday's airstrike.
"Turkish and international non-governmental organizations should investigate the incident and the U.N. Human Rights Committee should send a committee right away."
Erdogan's government, which has admitted that those killed were civilian smugglers whom the military mistook for Kurdistan Workers Party (PKK) militants, has promised not to allow a cover-up of the incident.
"We are waiting for the investigation results. We will share its results with the public," Deputy Prime Minister Bulent Arinc told reporters on Friday.
"These incidents can take place in the process of the fight against terror."
IHD and Mazlumder said most of those killed near the border village of Uludere were between the ages of 12 and 18. Turkish media has reported that 28 out of the 35 dead belonged to the same extended family and carried the same surname.
In their report, IHD and Mazlumder quoted 19-year-old Haci Encu, who survived the attack and was in hospital, as saying the smugglers were a group of about 40-50 people with mules and were attacked by drones when they were crossing the border to Iraq.
"We were going for sugar and diesel. We even heard the drone, but we kept on walking because it's our ordinary route," Encu is quoted as saying.
"The first drone killed 20 people, who were right on the border. We started running towards Iraq, and bombs started to fall on those who were left behind on the rocky area. We were six people in my group, and three of us survived. We had civilian clothes and nobody was armed," Encu said.
"The attack lasted around an hour. Me and a couple of other people with three mules, we went into a river, waited there for an hour and went out to hide beneath rocks," he said.
"We have been doing this for a long time. Two people from the group were married, the rest were high school and secondary school students. Nobody has contacted me for testimony yet, and I haven't seen a single soldier since the incident."
"CRIME AGAINST HUMANITY"
The funerals were expected to be held on Friday.
Turkey's largest pro-Kurdish party, the Peace and Democracy Party, or BDP, labeled the strike a crime against humanity, and has accused the armed forces of a cover-up.
The Turkish military had said its warplanes launched air strikes after drones spotted suspected PKK militants in the area. The military said there were was no civilian settlement in the area.
Turkish newspapers on Friday carried front-page pictures showing lines of corpses covered by blankets on a barren hillside, with weeping relatives around the bodies.
"Deadly intelligence," read pro-government Zaman.
The incident threatens to ignite more violence from the PKK, which is regarded as a terrorist organization by Turkey, the European Union and the United States. The group has been fighting for an ethnic Kurdish homeland in a conflict that has claimed the lives of 40,000 people.
A PKK commander called on Kurds to rise up to what he called an organized and planned massacre.
"We call on all the people of Kurdistan and especially those of Hakkari and Sirnak to show their reaction against this massacre and to hold the perpetrators of this massacre accountable through their uprising," Bahoz Erdal said in a statement.
With most Turks favoring a hardline military response against the PKK, the incident is unlikely to hurt the popularity of Erdogan, who won a third term in office in a June vote.
Smuggling is an important source of income for locals in provinces along the Iraqi border, with many villagers involved in bringing fuel, cigarettes and other goods from Iraqi villages. PKK militants also cross the border in these areas.
(Additional reporting by Ece Toksabay and Daren Butler in Istanbul; Writing by Ibon Villelabeitia)