ANKARA, Turkey (AP) — Turkish authorities on Sunday declared new 24-hour, indefinite curfews for two mainly-Kurdish towns where Turkey's security forces are set to launch large-scale operations to battle Kurdish militants.

Turkey has imposed curfews in several flashpoints in the southeast since August to root out militants linked to the Kurdistan Workers' Party, or PKK, who had set up barricades, dug trenches and planted explosives. The military operations have raised concerns over human rights violations and scores of civilian deaths. Tens of thousands of people have also been displaced by the fighting.

The governor's office for Hakkari province, which borders Iraq and Iran, said a curfew would take effect in the town Yuksekova at 2000 GMT (4 p.m. EDT) Sunday, adding that entering and leaving the town would also be banned. The announcement came as news reports said dozens of tanks had been deployed to the town.

Soon after, authorities in Mardin province announced that a round-the-clock would take effect in the town of Nusaybin — on the border with Syria — at midnight.

Residents were seen leaving Nusaybin on Sunday, packing cars or heading toward the bus terminal even before the curfew was announced, the Dogan news agency reported. Some tanks were parked at a school ahead of the planned offensive, it said.

Turkey's military last week ended a three-month operation against the militants in the historic Sur district of Diyarbakir — the largest city in the country's mostly Kurdish southeast. On Sunday, authorities eased the curfew in some streets and one neighborhood of Sur, but the siege over the district's main areas was still in place.

The PKK has been designated a terrorist organization by Turkey, the U.S. and the European Union. A fragile peace process between the PKK and the Turkish state collapsed in July, reigniting a battle that has cost tens of thousands of lives since 1984.