By Seda Sezer
ISTANBUL (Reuters) - Suspected Kurdish militants ambushed a Turkish military bus in western Turkey on Thursday in an attack which police said killed one soldier and wounded at least 11 people, adding to a recent upsurge in separatist violence.
If confirmed as a Kurdistan Workers Party (PKK) attack, the ambush in the Aegean province of Izmir would represent a widening of the conflict with the PKK beyond its regular field of operation in the mainly Kurdish southeast of Turkey.
The violence is a headache for Prime Minister Tayyip Erdogan as he seeks to limit the impact on Turkey of the conflict in Syria, where the PKK is exerting growing authority in some areas and receiving arms from Syrian forces, according to Ankara.
"This is unfortunately another example of the steps taken in widening terrorism," Erdogan told reporters in his first comments on the attack.
PKK rebels detonated explosives on the road before firing on the bus at 8 a.m. (0500 GMT) near Foca, a small resort town on the Aegean coast where there is a naval base, Dogan news agency said. The soldiers in the bus returned fire, it said.
Police declined to comment on who could be behind the assault and there was no immediate claim of responsibility. Attacks on military vehicles are common in southeast Turkey, but are rare in the rest of the country.
Television images showed the bus with its windows blown out and glass strewn across the road, and investigators in white overalls searching the scene.
Wounded soldiers were taken to a nearby hospital, a police spokeswoman said. It was unclear if the 11 wounded people included any civilians.
The attack occurred at a time of intensified clashes between the army and the PKK, whose 28-year-old armed struggle has cost more than 40,000 lives, most of them Kurds.
ASSAD ARMING PKK?
The rebels have fought for autonomy in the southeast since 1984. Turkey, the United States and the European Union list the PKK as a terrorist organization.
Clashes are focused east of the Syrian border. Turkish officials believe Syrian President Bashar al-Assad is arming PKK rebels, following a sharp deterioration of ties between the two countries since the start of the Syrian uprising 17 months ago.
Erdogan has become one of Assad's most vocal critics.
Turkey's Foreign Minister Ahmet Davutoglu repeated the allegations about Assad arming the PKK while travelling to Myanmar overnight, according to Turkish media.
"Assad gave them weapons support. Yes - this is not a fantasy. It is true. We have taken necessary measures against this threat," Davutoglu was quoted as saying.
Turkish armed forces have clashed with PKK fighters around the remote, mountainous district of Semdinli, close to the borders with Iraq and Iran, since late July after the militants set up checkpoints in the area.
Erdogan said 115 PKK militants had been killed in the fighting there so far. Journalists and other non-residents have been barred entry to the area.
Murat Karayilan, the acting PKK leader, said last week the group was changing tactics with its battle in Semdinli, according to Firat News, a website close to the militants.
Instead of their traditional hit-and-run ambushes on Turkish security forces, PKK fighters will remain positioned in Semdinli in an attempt to form a stronghold there, he said.
(Reporting by Seda Sezer; Writing by Daren Butler and Alexandra Hudson; Editing by Alistair Lyon)