Istanbul (AFP) - The outlawed Kurdistan Workers' Party (PKK) on Friday claimed a suicide truck bombing on a police building in Turkey's southeast that killed 11 officers and wounded dozens more.
The blast came two days after the Turkish army launched an offensive in Syria that the government says is targeting both Islamic State (IS) jihadists and a Syrian Kurdish militia detested by Ankara.
The explosion tore the facade off the headquarters of the Turkish riot police in the town of Cizre, a bastion of PKK support just north of the Syrian border.
The local governor's office said 11 officers were killed and 78 people injured, three of them civilians. Four people were said to be in critical condition.
The state-run Anadolu news agency said the explosion took place 50 metres (yards) from the building, at a control post.
The PKK said it carried out the assault in retaliation for the "continued isolation" of the group's jailed leader Abdullah Ocalan and the "lack of information" about his welfare.
Cizre, a majority Kurdish town, has been badly hit by renewed violence between the PKK and government forces since the collapse of a ceasefire last year.
Turkish security forces have been hit by near daily PKK attacks since a two-and-a-half year truce ended in July 2015, leaving hundreds of police officers and soldiers dead.
- 'Bare-faced lie' -
Turkey's operation in Syria aims to push both IS and the Kurdish People's Protection Units (YPG) militia that is fighting the jihadists out of the border area.
Ankara considers the YPG, which has links to the PKK, as a terror group bent on carving out an autonomous Kurdish region.
Speaking during the inauguration of a new bridge over the Bosphorus in Istanbul Friday, President Recep Tayyip Erdogan said the Cizre attack showed Turkey was "right to keep the operation in Syria broad to include all terrorist organisations".
Western media have suggested he is more intent on preventing Syrian Kurds joining up areas under their control than fighting IS.
Prime Minister Binali Yildirim rejected the allegations.
"They either know nothing about the world or else their job is to report a bare-faced lie," he told a press conference with his Bulgarian counterpart.
Ankara's hostility to the Syrian Kurdish fighters has put it at odds with its NATO ally, the United States, which supports the YPG militia in the fight against IS.
On Wednesday, Turkish tanks and fighter jets helped pro-Turkish rebels rout IS from the town of Jarabulus, on which the YPG appeared to have designs.
A day later, Turkey shelled Kurdish fighters in the area, saying they were failing to observe a deal with the US to stop advancing west.
Anadolu quoted security sources as saying the military would continue to intervene against the Kurdish fighters until they began to retreat.
Murat Karayilan, one of the top Iraq-based leaders of the PKK, questioned the apparent lack of resistance from IS in Jarabulus.
"ISIS has never abandoned a town in one day without putting up a fight," he told the pro-PKK Firat news agency, accusing Turkey of doing a deal with the extremists
In a separate incident on the border, three Turkish soldiers were injured by mortar shells fired from Syria that landed in Yayladagi district, Dogan news agency reported.
The agency said there had been clashes between local Turkmen and Syrian regime forces in Latakia, from where the shells were fired.
- Aid for Aleppo -
Erdogan and Russian counterpart Vladimir Putin -- who until late June had been locked in a bitter feud over the shooting down of a Russian war plane -- agreed to step up efforts to ensure aid reached Syria's conflict-torn northern Aleppo province.
The two also emphasised the need to fight "all terror groups" in Syria, Anadolu said.
On a visit to Turkey this week, US Vice President Joe Biden said Washington had warned YPG not to move west of the Euphrates river, or risk losing American support.
Back in Turkey, the PKK has kept up its assaults following the unsuccessful July 15 coup by rogue elements in the military.
The government for its part has vowed to press on with the campaign to eradicate the group from the country's east.
Over the past year, the army has conducted several operations in towns and cities in the southeast that have claimed civilian lives, including in Cizre.
Over 40,000 people have been killed since the PKK first took up arms in 1984 with the aim of carving out an independent state for Turkey's Kurdish minority.
It is proscribed as a terrorist group by Turkey, the European Union and the United States.