A remote controlled roadside bomb killed three Turkish soldiers and wounded four others in the country's turbulent southeast.
The bomb, believed to have been planted by Kurdish rebels near the southeastern city of Sirnak, went off as a military vehicle was returning from an operation, killing a major, a lieutenant colonel and a private, a local official said.
The official spoke on condition of anonymity, citing regulations that Turkish civil servants are not allowed to speak to the press without prior authorization.
The major and lieutenant colonel were the highest ranking officers killed recently in clashes with rebels active in Turkey's southeast along its border with Iraq.
The roadside bombing came the day after Turkish Army declared its "unshakable determination" to defeat Kurdish rebels. Earlier this week, a similar bomb claimed lives of four troops.
Turkey is increasingly frustrated with the surge in attacks by the Kurdish guerrillas and has been building up its forces near the Iraqi border, raising fears it might stage a cross-border operation.
Military and political leaders have been debating whether a large scale attack would strain Turkey's ties with the United States and European Union.
The U.S. has warned against such an incursion, fearing it might drag northern Iraq, the relatively stable part of the war-torn country, into chaos. Turkish military has shelled suspected rebel bases in Iraq's north this week.
Earlier Saturday, Iraqi Foreign Ministry said it summoned the top Turkish diplomat in Baghdad and called for an immediate halt to the shelling, saying such actions "undermine confidence between the two nations and negatively affect their friendship."
The province of Sirnak, where the bombing took place is inside one of the three "security zones" Turkish Army declared near the Iraqi border.
Rebels of the Kurdistan Workers' Party, also known for its acronym PKK, have been fighting the Turkish government for autonomy in a decades-long war that caused more than 37,000 lives. The United States and the European Union brand PKK a terrorist organization.