Two of the rebels were killed in a mountainous area in the province of Hakkari, near the borders with Iraq and Iran, where a military operation against the separatist Kurdistan Workers' Party (PKK) has been under way since last week, the office of the Hakkari governor said.

A soldier was also injured in the shootout.

Separately, a soldier and a rebel were killed in fighting that broke out late Monday during a security sweep of the countryside for PKK militants near Pervari town, Siirt province, security officials said.

Meanwhile, police in the eastern city of Tunceli on Tuesday detained 23 people -- most of them members of the country's main Kurdish party, the Democratic Society Party (DTP) -- on suspicion that they had links with the PKK, local sources said.

The DTP condemned the detentions as the latest move in an official campaign to put pressure on the party since late March when Kurdish riots shook urban centres for a week, claiming 16 lives.

"Since the latest incidents, several party headquarters have been raided and some 50 senior members have been illegally and arbitrarily detained," the DTP said in a statement.

Turkish officials have accused the PKK of orchestrating the riots and the DTP of toeing the PKK line by repeating the banned organization's appeal for civil disobedience.

Violence has been on the rise in the southeast since the riots, which were followed by clashes in the countryside between the army and the PKK.

More than 37,000 people have been killed since 1984 when the PKK, blacklisted as a terrorist group by Ankara, the European Union and the United States, took up arms for self-rule in the southeast.