A separatist Kurdish militant detonated a bomb inside a fuel tanker, at a road block near a military outpost, killing himself and another person inside the vehicle.
The militant had hijacked the fuel tanker four hours before Saturday's explosion, which occurred at a road block, some 150 meters (yards) away from the Karsilar military outpost, in the eastern province of Tunceli, the military said.
It was not clear from the military statement if the initial target of the attack was the military outpost or soldiers at the road block itself.
Earlier, officials from the local governor's office said two militants were killed when guards fired at the fuel tanker, stopping them from ramming it into the military outpost. The tanker caught fire and exploded, the officials said.
But a military statement said the tanker exploded after a Kurdish guerrilla set off a bomb inside the vehicle. The discrepancy between the two reports could not immediately be explained.
The military did not identify the second person but the state-run Anatolia news agency said the hijacked tanker's driver was inside the vehicle and was killed alongside the militant in the explosion.
The military statement said another group of rebels later attacked the Karsilar outpost with automatic rifles, but no one was killed in that attack.
The Turkish military is carrying out several offensives against the rebels in southeast Turkey, while the country's political and military leaders are debating whether to stage an incursion into northern Iraq to try to root out rebel bases there.
Turkey has been building up its military forces on the Iraqi border amid stepped-up attacks by the rebels of the Kurdistan Workers' Party, or PKK, who often stage raids in southeast Turkey after crossing over from hide-outs in Iraq.
Earlier this month, Kurdish rebels rammed a vehicle into another military outpost in Tunceli province and attacked it with hand grenades and automatic weapons, killing seven soldiers. Karsilar was the target of a similar attack last year, which killed two soldiers.
PKK guerrillas took up arms in 1984, and tens of thousand of people have died in the conflict for autonomy in southeast Turkey.
The U.S. and European Union brand the PKK a terrorist organization.
The United States is opposed to a large scale incursion for fear of seeing the relatively stable part of war-torn Iraq slide into chaos.
In other fighting, three rebels were killed Saturday in a clash in the province of Hakkari, near the border with Iraq, the military said. A government-paid village guard and two other rebels were also killed Saturday in a separate clash near the town of Silvan, in Diyarbakir province, the military said.
Also Sunday, thousands of people gathered in a main square in the northwestern Turkish city of Bursa to protest PKK violence that has killed more than two dozen soldiers since May.
More than 1,000 Turks marched silently in Istanbul in a similar protest Saturday.
The protests followed a call by the Turkish military for people to show "mass reaction" to the rebel attacks.