Ten soldiers were killed and seven wounded in the attack in the province of Sirnak, the local government said, while other sources said about 20 members of the outlawed Kurdistan Workers’ Party (PKK) were also killed.
Provincial governor Vahdettin Ozkan said the militants had attacked the security complex at Beytussebap, which lies about 40 kilometres (25 miles) from the Iraqi border, late Sunday.
Police and soldiers returned fire, triggering some of the deadliest clashes with the rebels seen in months.
“The fight against terrorism will continue in all its aspects,” Deputy Prime Minister Bekir Bozdag said in televised remarks.
Last month, 10 people including civilians were killed in a car bomb attack blamed on the separatist Kurds in the southeastern city of Gaziantep which caused national outrage.
The government had launched a large-scale military offensive against the PKK on July 23 that it said early last month killed a total of 115 Kurdish rebels.
In one of the deadliest recent single incidents, fighting in June between Turkish soldiers and Kurdish rebels killed 28 people after an attack by PKK members on an army post near the Iraqi border.
In another incident in the southeast late Sunday, clashes erupted when rebels refused to heed police calls to stop at a checkpoint on a highway in the province of Sanliurfa and instead shot at police, NTV television reported.
Three members of the security forces and one civilian were wounded, along with one Kurdish rebel in the fighting in the province which borders Syria, according to the private television station.
Rebels in the vehicle attempted to flee the scene but were blocked by security forces, and one left the car and blew himself up, NTV said.
It said police had received tip-offs that Kurdish suicide bombers had infiltrated from neighbouring Syria for attacks inside Turkey.
The PKK has stepped up its assaults against Turkish security forces in recent months, with Turkish officials and the local media linking the surge to the brutal conflict raging in neighbouring Syria.
Prime Minister Recep Tayyip Erdogan has threatened military intervention if the Kurdish rebels set up bases in Syria.
He condemned the latest attack and said the PKK had become a “puppet” of hostile foreign forces.
“The terrorist organisation which has become a puppet of shady international groups may carry out this cowardly scenario, this villainous provocation if it so pleases,” he said in condolences to the armed forces chief of staff, quoted by Anatolia news agency.
But he added that “we, as a nation, will never allow these assassins to achieve their objective.”
Some government officials believe that Damascus — once backed by Ankara — is helping the PKK in retaliation for Turkey’s support for rebels fighting President Bashar al-Assad.
The PKK, considered a terrorist group by Turkey and much of the international community, took up arms in Kurdish-majority southeastern Turkey in 1984, sparking a conflict that has claimed about 45,000 lives.