Abdul Rahman Jaderji, a senior official in the PKK in northern Iraq, said the rebels had killed 40 soldiers. The number could not be independently verified.
The pro-PKK Firat news agency, which is based in western Europe, said eight soldiers had also been taken hostage. Gonul denied any soldiers had been kidnapped.
"We cannot give details on how many we have captured, all I can say is that they are not in Iraq. They are in Turkey," a senior PKK source told Reuters.
In a separate incident on Sunday, a landmine killed one civilian and wounded at least 13 more in a minibus travelling in a wedding convoy near to where the soldiers were killed.
Ankara blames the PKK for the deaths of more than 30,000 people since the group launched its armed campaign for an ethnic homeland in southeast Turkey in 1984. The United States, Turkey and European Union class the PKK as a terrorist organisation.
Some 3,000 PKK rebels, including its leaders, are believed to be based in camps in the mountainous region of northern Iraq.
Iraq's government said it was taking important steps to end what it called the "terrorist actions" of the Kurdish rebels.
But Iraqi Kurdish leader Masoud Barzani said his autonomous region would defend itself if Turkish troops invaded.
"We are not going to be caught up in the PKK and Turkish war, but if the Kurdistan region is targeted, then we are going to defend our citizens," Barzani told reporters after meeting Iraqi President Jalal Talabani, who is also a Kurd.
Talabani called on the PKK to cease fighting and to turn itself into a political organisation. "If they insist on continuing to fight they must leave Iraqi Kurdistan," he said.
Turkey's military has deployed as many as 100,000 troops, backed by tanks and attack helicopters, along the border.
With the death toll among Turkish security forces around 40 for the past month alone, Erdogan's government is under heavy domestic pressure to pursue the PKK into northern Iraq.
Turks staged anti-PKK rallies after Sunday's deaths.
Erdogan has appeared reluctant to launch an incursion, and Western diplomats said Turkey was concerned about the security, diplomatic and economic risks of such a move, but the latest rebel attacks may have made a military strike inevitable.
