Turkish army says it has killed 153 rebels and lost 17 soldiers since it launched cross-border incursion.
Turkish troops, backed by fighter jets, closed in on a main rebel base Tuesday in their offensive against Kurdish separatists in northern Iraq that has so far claimed at least 170 lives.
Regional security forces in the Kurdish-administered autonomous region reported sustained fighting overnight as Turkish soldiers advanced on the base in the Zap area.
The camp, situated in a deep valley just a six-kilometre walk from the Turkish border, has been identified by the military as a major staging post used by Kurdistan Workers' Party (PKK) rebels to launch attacks into Turkish territory.
The Turkish army says it has killed 153 rebels and lost 17 soldiers since it launched its cross-border incursion against PKK bases in northern Iraq on Thursday evening.
Ankara says an estimated 4,000 rebels use the region as a safe haven to organise cross-border raids in their struggle for self-rule in southeast Turkey.
The PKK, whose armed separatist campaign has claimed more than 37,000 lives since 1984, claims to have killed 81 soldiers since the offensive began.
Baghdad and Washington have both called on Ankara to show restraint and wrap up its offensive as soon as possible.
"We hope that this is just a short-term incursion," White House spokeswoman Dana Perino told reporters Monday.
US Defence Secretary Robert Gates was in India and scheduled to fly Wednesday to Ankara for talks on the military action.
The US has provided Turkey with real-time intelligence on rebel movements, but is deeply concerned that a long-term offensive might undermine one of Iraq's relatively stable regions.
Turkey insists the Kurdistan Workers' Party (PKK) are the sole operational target and that its troops will pull back once they have achieved their objective of flushing out the rebels.
Clashes continued in the mountainous Hakurk area to the east, close to Iraq's border with Iran, where the Turkish army air-dropped troops and helicopter gunships pounded rebel positions on Monday.
PKK fighters suffered "heavy losses under fire from close quarters" as they tried to escape, the Turkish general staff said in a statement Monday.
Warplanes hit around 30 targets deep in northern Iraq on the route of the Turkish advance, it said.
Turkey's President Abdullah Gul, Prime Minister Recep Tayyip Erdogan and Army Chief Yasar Buyukanit joined thousands in Ankara Monday for the funeral of three soldiers slain in the offensive as mourners chanted anti-PKK slogans.
In Diyarbakir, the main city in the mainly Kurdish southeast of Turkey, up to 10,000 people spilled into the streets in protest against the government for ordering troops into northern Iraq.