By Sarah Rainsford
BBC News, Istanbul
Officials have honoured troops killed in previous clashes
All day Turkish news anchors have been reading out the names of 13 soldiers killed in Sirnak by the PKK.
There have been pictures of their families clutching photographs of young men in uniform.
The elite troops were ambushed during an operation in the mountains close to the Iraqi border.
It was part of an offensive against the Kurdish separatist PKK that began earlier this year.
Turkish media calculate that 97 soldiers have died in 2007 alone. But this is the highest number killed in one attack in many years.
The previous weekend, 12 passengers were taken from a minibus and shot in the same province.
That was also blamed on the PKK, which has been labelled a terrorist organisation by the EU and the US.
Demand for retaliation has been almost immediate.
Ankara argues that the PKK gets vital support from Northern Iraq, where it says some 3,000 fighters are based.
In recent months there have been mounting calls for a cross-border military operation to target them, and deep frustration at US inaction against the threat.
That rhetoric has now increased, putting the government under pressure to act.
"Our grand nation expects a determined and permanent solution against terror and separatism," nationalist MHP party leader Devlet Bahceli wrote in a statement.
He insists Turkish troops have the right to cross the border, for the sake of national security.
"If such determination is delayed it is clear that deep wounds will open and our unity will be damaged," Mr Bahceli wrote.
The government has reiterated its determination in the fight against terror but has so far resisted sanctioning any operations inside Iraq. Washington and Baghdad are strongly opposed.
On Monday, though, government spokesman Cemil Cicek indicated that no option had been excluded.
The PKK wants autonomy in south-eastern Turkey
"Our government is determined to take every measure possible, if it will be useful to stamp out terrorism," he said.
Sahin Alpay, a columnist on Zaman newspaper, says the attacks are "definitely creating an atmosphere where there are calls for severe repressive measures, possibly a push for military intervention".
"But that would be really crazy," he adds.
"Everyone knows most of the PKK is based inside Turkey. It's a distortion to pretend this problem is imported from abroad."
Formed in the late 1970s, the PKK was originally a radical Marxist group intent in establishing an independent Kurdish state.
After 15 years - during which 37,000 people were killed - PKK founder Abdullah Ocalan was captured and imprisoned in 1999.
A lull in fighting lasted until two years ago, when the clashes resumed.
Earlier this year they intensified.
Some here believe the PKK, which is also linked to smuggling activities, is aiming to sabotage "normalisation" efforts in the region to protect its illegal business interests.
Others suggest it is being used by other forces in Turkey opposed to deeper democratisation and EU accession.
The PKK itself claims to fight for political and cultural rights for ethnic Kurds.
This summer, pro-Kurdish politicians were elected to parliament for the first time in 15 years.
The inclusion of the DTP party lifted hopes that the Kurds' complaints could be addressed in a peaceful, democratic forum instead.
But the Sirnak attacks are likely to hinder that, particularly as the DTP refuses to label the PKK as terrorists.
Those arguing for an exclusively militaristic approach are gaining the upper hand again.
"This ambush suggests the military has to rethink its entire strategy in the south east," says Retired Brig-Gen Haldun Solmazturk, who fought in the region himself for many years.
He believes military units that were disbanded along with emergency rule in the region in 2002 should return on a permanent basis.
"Military action alone is not enough, but we must face facts," he says.
"If the PKK can wander around today and kill 12 or 13 people, then there is a serious problem. It's one that needs to be addressed."