ISTANBUL // Nearly a year ago, under cover of darkness, Turkish jets bombed a line of Kurdish smugglers on a mountain path as they brought cigarettes and petrol on donkeys into Turkey from Iraq. The night-time bombing killed 34 people, about half of them teenage boys.
The bombing, ordered after the smugglers were falsely identified by the military as a unit of a Kurdish rebel group, caused a national outcry, not only because of the high number of innocent victims, but also because the attack signified the brutality with which the Kurdish conflict is being fought.
Ahead of this week's anniversary, Kurdish activists and the opposition have accused the government of a cover-up and failing to investigate the deaths properly.
The perceived lack of a proper investigation heightened tensions between the government and the Kurdish community during a year in which clashes between the army and Kurdish rebels have surged.
More than 40,000 people have been killed in the conflict between Turkey and the Kurdistan Workers' Party (PKK), which has been fighting for Kurdish self rule in Turkey's south-east since 1984.
The attack, near the town of Uludere, or Roboski in Kurdish, was ordered after military surveillance drones circled over the group. The government says the attack was a tragic mistake because the smugglers were thought to be a unit of Kurdish rebels trying to enter Turkey to stage attacks.
Despite promises by the government that the incident would be thoroughly investigated, official inquiries have failed to produce tangible results. No arrests have been made.
The pressure on the government is increasing as Kurds commemorate on Friday those killed in the attack. The Congress for a Democratic Society, a Kurdish umbrella group, has called on supporters to gather at the scene of the raid on the anniversary.
Kurdish politicians have called the attack a "massacre" and said that the government of Recep Tayyip Erdogan, the prime minister, was responsible for the deaths but wanted to dodge the blame.
"Both the government and the military know exactly what went on in the Roboski massacre, minute by minute, but they keep the information from the public," said Ertugrul Kurkcu, an Ankara-based Kurdish legislator.
Mr Kurkcu, of the Party for Peace and Democracy (BDP), Turkey's main Kurdish party, said the air raid had been launched within the framework of regulations governing cross-border raids by the Turkish military into Iraq to bomb Kurdish rebel positions.
"That means the attack must have been ordered by the government, because the air force does not send jets into Iraq on its own," he said.
Kemal Kilicdaroglu, the leader of the Republican People's Party (CHP), the biggest opposition bloc in Ankara's parliament, called the government a "culprit" during a budget debate this month.
"They went and killed 34 of our citizens," Mr Kilicdaroglu said, going on to claim that the government was refusing to "be accountable to the people and to parliament".
Mr Erdogan rejected the accusations of a cover-up and said the government had apologised to the relatives of the victims and agreed to pay compensation. He has also said that the PKK has been trying to capitalise on the criticism levelled against the government. Coffins of bombing victims were draped in PKK flags at the funeral.
But Mr Kurkcu, of the BDP, said the government was not telling the whole truth about the incident because it wanted to protect itself.
"The order to shoot [on the smugglers] may have come directly from the prime minister," he said. "There is no political will to clear up the event because the operation was ordered by the government itself."
Whatever the reasons, many questions about the raid remained unanswered. A commission of inquiry in Turkey's parliament had so far failed to come up with concrete findings as to who ordered the attack and why.
News reports said commission members belonging to Mr Erdogan's ruling Justice and Development Party (AKP) had suggested putting the blame for the raid on shortcomings and insufficient coordination within the security apparatus.
Mr Kurkcu and Levent Gok, another opposition member of the commission, said meetings of the commission had been cancelled twice this month in an apparent attempt by the government to prevent the report from being finalised. "They want to put people to sleep," Mr Kurkcu said.
An ongoing criminal investigation launched in south-east Turkey was also criticised as an attempted whitewash because prosecutors were refusing to inform relatives of the victims and their lawyers about the progress of the inquiry.
Mr Erdogan has drawn additional criticism by publicly suggesting that smugglers on the Iraqi border may have links to the PKK. In a speech in May, he asked why smugglers in the region never stepped on mines along the border. Referring to the PKK, he added that someone might provide the smugglers with maps designating minefields.
Smuggling has a long tradition in the border area, but authorities mostly look the other way because the illegal imports provide income for poor families in the region.
According to news reports, the absence of any tangible progress in the Uludere investigations has caused concerns to be voiced within Mr Erdogan's AKP, a rare development in a party known for its unquestioning loyalty to the prime minister.
Several AKP members from the Kurdish region told Mr Erdogan in a recent meeting that they were on the defensive in their constituencies because of the lack of progress. Mr Erdogan told them to stress that the judicial investigation was ongoing and that the government had not kept anything hidden from the public.
The Kurdish region is expected to be a focal point of local elections scheduled for 2014, with the AKP and the BDP vying for the position of strongest party.