ISTANBUL - Prime Minister Recep Tayyip Erdogan served as a pallbearer at a funeral yesterday for some of the 17 people killed by bombs in Turkey's biggest city, an attack the government blamed on Kurdish rebels who have targeted civilians in the past.
The rebel Kurdistan Workers' Party, also called the PKK, immediately denied responsibility and attributed Sunday's attack to "dark forces" - hard-line Turkish nationalists who allegedly seek to foment chaos to strengthen the political influence of the military.
No one has claimed responsibility for the bombings, and Turkey is home to a variety of violent groups besides the PKK, including Islamic extremists and alleged coup plotters with ties to the secular establishment.
At the funeral, thousands of mourners surged around 10 coffins draped in the red and white Turkish flag at the foot of a mosque in Gungoren, a mostly residential neighborhood near Istanbul's international airport that houses many poor migrants.
Erdogan said the bombings appeared to be a reprisal for air raids on PKK positions in northern Iraq, as well as a cross-border ground offensive by the Turkish military in February.
The blasts were the deadliest against civilians in five years.
"Unfortunately, the costs of this are heavy," Erdogan said. "The incident last night is one of them."
Some analysts agreed.
"The PKK seems to be the most likely instigator if you look at the type of explosives and the bomb mechanism used," Sedat Laciner of the Ankara-based International Strategic Research Organization told NTV television.
"The terrorist organization has been trying to stage attacks that would shock people at times of high tension, especially recently."
One analyst did not rule out PKK involvement, but said the use of coordinated bombs in a place of no obvious relevance or symbolism to the rebels' fight against the Turkish state did not resemble tactics previously used by them.
"It's not the sort of thing they normally do," said Aliza Marcus, author of "Blood and Belief: the PKK and the Kurdish Fight for Independence."
In the past, Kurdish militants have bombed more high-profile targets such as tourist resorts.
Marcus said the relative sophistication of the twin bombing was more reminiscent of attacks by Al Qaeda-linked militants, but cautioned: "There's never any shortage of suspects in Turkey who want to cause some sort of disarray."
The twin blasts happened on the eve of a Turkish court's deliberations on whether to ban the Islamic-oriented ruling party for allegedly trying to undermine secularism, and the timing raised questions about whether there was a link.
The bombings and the legal challenge to the government highlight a growing mood of uncertainty in Turkey, where an Islamic-oriented government that won a strong mandate in elections last year is locked in a power struggle with secular circles in the military and judiciary.
The attack could benefit militants by sowing more suspicion among Turkey's feuding power circles.