By Sarah Rainsford
BBC News, Istanbul
Ten victims of Sunday's bomb blasts in Istanbul were buried on Monday, each coffin wrapped in the red and white Turkish flag.
The bombs in an Istanbul suburb killed 17 people and injured more than 150
Prime Minister Recep Tayyip Erdogan was among the pall-bearers.
Two bombs were detonated in quick succession on Sunday evening on a crowded pedestrian street.
The blasts killed 17 people and injured more than 150.
At the funeral, some nationalists chanted slogans damning the Kurdish rebel PKK group.
The Istanbul governor says the group - labelled a terrorist organisation by the US and EU as well as Turkey - appears to be linked to the blasts.
The governor gave no details and a spokesman for the PKK denied any involvement.
"There are many groups here who might carry out such attacks, including al-Qaeda cells and militant groups like Turkish Hezbollah. We can't be sure," said Nihat Ali Ozcan, of Turkey's Tepav foundation.
This can mark the start of more unstable days. The PKK is carrying out more and more wild operations. The smaller they get, the more out of control they become
Sedat Laciner, Usak think tank
But like many analysts here, he suggests the most convincing culprit so far is indeed the PKK.
While Islamic extremists do operate in Turkey, they have a history of hitting specific targets - usually related to the West - a description that hardly matches the anonymous residential district of Istanbul bombed on Sunday.
Right and left-wing militants are also active in Turkey - although not usually linked to this kind - or scale - of attack.
The bombs follow a series of air-strikes by Turkish warplanes on suspected PKK targets inside northern Iraq.
The most recent raids were confirmed by the military on Monday, which claims to have inflicted significant damage.
Funerals for the victims were held the day after the blast
Some have therefore suggested the PKK may have planted the devices in Istanbul in retaliation - and to prove that the group, first formed in the 1980s, is still a force to reckon with.
"If not, PKK followers start to ask what it's doing for them. They start to lose support," Nihat Ali Ozcan said.
The bomb attack has come at a time of real tension in Turkey.
The governing AK Party (AKP) won 47% of the vote at the last election.
But the party is currently on trial and facing closure - accused of attempting to Islamise this strictly secular state.
It denies the charge and many see the case as the climax of a bitter power struggle between Turkey's traditional ruling elite and the up-and-coming class represented by the AKP.
That battle recently took a turn into far darker waters.
Last week, a court agreed to try more than 80 suspects - including two retired generals ľ who are allegedly linked to an ultra-nationalist plot to overthrow the government.
The suspects, from a group known as Ergenekon, are accused of planning a series of explosions and assassinations to create chaos in Turkey and force a military takeover meant to "save the republic".
Some wonder whether elements linked to that plot who are not yet in custody could be behind Sunday's attack.
"If the country is out of control with no proper governance, if bombs explode here and there, then it's impossible to know what might happen," mused Sedat Laciner of the think tank Usak.
"That might create the atmosphere for a coup, when they say 'forget the closure case, and the Ergenekon plot - the priority is security and the fight against terror.'"
PKK or otherwise, no hard evidence has yet been made public. But if this is the work of Kurdish rebels, commentators worry it may not be an isolated attack.
"This can mark the start of more unstable days," Mr Laciner says. "The PKK is carrying out more and more wild operations. The smaller they get, the more out of control they become."