Following the double bomb attack in Istanbul at the weekend, the spotlight has turned on the Kurdish rebel group, the PKK. The BBC's Clive Myrie tells how he recently travelled to northern Iraq to put allegations of terrorism to the group's leader.
Murat Karyilan did not want the BBC to use its own equipment
We set off early in the morning, unsure exactly where we would end up - though we knew we were heading towards the Qandil Mountains of northern Iraq.
It is classic bandit country and home to one of the world's most durable guerrilla groups - the Kurdish separatist PKK.
We were told not to bring any TV equipment. As you can imagine, this is not what a TV correspondent and crew want to hear.
"Don't worry, they will provide everything," my contact kept telling me.
The PKK were taking no chances, after the assassination of one tribal leader in Afghanistan with an explosive device placed inside a TV camera back in 2001.
To get to the PKK you have to cross Kurdish Regional Government or KRG checkpoints - we kept a low profile in the back of the car as we drove through.
It's possible we will start a campaign of attacks against economic and military targets in Turkish cities
Murat Karyilan Leader of the PKK
Eventually we reached land controlled by the outlawed PKK, a good four hours into our journey.
A little later a white pick-up truck pulled up behind us all of a sudden and motioned for us to pull over.
Inside was a PKK fighter, who after a few words with our driver in Kurdish, got back in his vehicle and drove off.
We followed, climbing ever higher into the Qandils with barely a couple of feet between us and a sheer drop hundreds of feet down into the valley.
The road was bumpy, the heat was stifling, I was getting fed up.
A few minutes later we stopped in a tiny village - I am not allowed to reveal its name - and soon another white pick-up truck arrived with rebel fighters in grey uniforms, armed with AK-47 rifles.
It was the first vehicle of a convoy containing the car of the leader of the PKK - Murat Karyilan.
'Struggling for rights'
The scene was like something out of 1960s South America. There were men and women all around in this green lush village wearing army fatigues, with Kalashnikov rifles slung over shoulders or propped against walls.
The BBC's Clive Myrie talks to PKK leader Murat Karyilan
The image of Che Guevara graced the wooden butt of one AK. There were vegetable patches and clearly an area where chickens were killed and plucked for dinner.
There was a small building at the end of a clearing which was an impromptu television studio, with lights and pictures on the walls of the founder of the PKK, Abdullah Ocalan, now serving a life sentence for terrorism offences in solitary confinement in Turkey.
They gave us lunch and then, under the shade of a walnut tree swaying in a light breeze, the PKK also gave us what we came for - an exclusive interview with the leader of the guerrilla group.
Murat Karyilan looks like a kindly old uncle, as he sips tea in front of me. In his late 50s now, he is a 30-year veteran of the campaign for Kurdish rights in Turkey, and leader of the PKK since Ocalan's capture back in 1999.
He is dressed in army fatigues, exuding the quiet confidence of a man secure in the knowledge that what he is doing is right.
But how can that be? How can anyone justify killing others to further one's political aims? I press home the fact that no-one can justify murder, whatever the cause.
"No," he says, "what they are doing is unjust."
"We are struggling for our rights... for Kurdish freedom, we have no other way to defend ourselves against the might of Turkey."
The European Union and United States say the PKK is a terrorist group.
It has launched attacks not only on Turkish troops in the south-east of the country, but on civilians in Turkey's major cities and tourist resorts. More than 30,000 people have been killed since it took up arms in 1984.
But Murat Karyilan says it is the Turkish authorities who are the true aggressors.
The PKK has launched many attacks across Turkey
"The Turkish military attack our people - the Kurds - inside the country, killing and torturing... This is a war.
"Yes, it is true sometimes we make mistakes - and we are sorry... but our policy is not to attack civilians."
For many in Turkey that is rubbish, and the double bomb attack in Istanbul on Sunday is proof.
The PKK has denied any involvement in that attack.
There is little doubt Turkey's Kurdish population has for a long time been treated as second class.
There have been improvements since 2000, but their language still is not taught in schools, and Kurdish programming on TV is restricted to one hour a week.
The PKK says Kurdish culture and heritage is being denied and Kurdish activists are routinely harassed and beaten.
Warning to Turkey
But the Turks say they will never countenance any loss of land or sovereignty, and so successive prime ministers have tried to crush the PKK.
Earlier this year thousands of troops, backed by fighter jets, crossed into northern Iraq, pinpointing PKK bases.
But Washington feared that a prolonged Turkish campaign might destabilise the one part of the country that has been relatively peaceful since the fall of Saddam Hussein. The incursion lasted just seven days.
Murat Karyilan saw the swift withdrawal as a victory for his fighters and he issued a warning to Ankara.
"It's possible we will start a campaign of attacks against economic and military targets in Turkish cities," he told me, "if their soldiers continue to attack us... we are prepared to do this."
The Turkish authorities say the coffins bearing the victims of Sunday's Istanbul bombs are proof that such a campaign has already begun.
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