DIYARBAKIR, Turkey (Reuters) - Gunfire clattered constantly and smoke rose on Thursday from two towns in southeast Turkey and President Tayyip Erdogan said Kurdish militants would be "annihilated" in an intensifying urban battle that has killed 25 Kurdish militants in two days.
The PKK's three-decades-old insurgency flared up again in July after the collapse of a two-year ceasefire, plunging Turkey's mainly Kurdish southeast back into open conflict.
Although traditionally rooted in the countryside, the PKK has shifted its focus in recent years to towns and cities in the southeast. The Ankara government has responded by cracking down with operations in border towns such as Cizre and Silopi, both of which were placed under curfew on Monday.
Erdogan said the operations would continue until the area was "cleansed" of the militants and their barricades and trenches destroyed.
"You will be annihilated in those houses, those buildings, those ditches which you have dug," he told a crowd in Konya. "Our security forces will continue this fight until it has been completely cleansed and a peaceful atmosphere established."
Ferhat Encu, a local deputy for the pro-Kurdish Peoples' Democratic Party (HDP), said the curfews there had "mutated into a process of destroying the towns", forcing people to flee.
"The untargeted attacks and shelling by security forces amount to an all-out attack on the Kurdish people by a government which wants to blockade neighbourhoods," he said in a text of parliamentary questions to the interior minister.
The two towns, in Sirnak province near the Syrian and Iraqi borders, became central targets for Turkey's latest anti-PKK operations in which Turkey's media says 10,000 police and troops, backed by tanks, are taking part.
Twenty-four PKK militants were killed in Cizre and one in Silopi in the latest operations, the Turkish military said in a statement. Eight members of the security forces suffered wounds that were not life-threatening.
Machinegun bursts echoed across Cizre on Thursday and smoke funnelled up from the town, overlooked by armoured vehicles parked on hills, after a spate of blasts and shooting overnight, with tracer fire lighting up the sky.
"Through resistance we will win!" Kurds could be heard chanting in Cizre, while others shouted, whistled and banged saucepans and children kicked store shutters in the darkened streets in a protest against the security operations. Witnesses said there were similar scenes in Silopi overnight.
Hospital sources said a 45-year-old mother of four, named as Hediye Sen, was killed during clashes in Cizre while a 70-year-old died of a heart attack during fighting in Silopi.
Witnesses said the towns' streets were largely empty and stores closed on Thursday and the Sirnak governor's office said security forces continued to dismantle barricades, fill ditches and remove explosive devices planted by the PKK.
In the region's largest city, Diyarbakir, two policemen were wounded in clashes in the historic district of Sur, security sources said. Elsewhere in the city, militants threw handmade explosives under an armoured police truck, triggering a brief clash between police and fleeing assailants.
The PKK launched its insurgency in 1984 and more than 40,000 people have been killed in the conflict. Peace talks between its jailed leader Abdullah Ocalan and the state ground to a halt early this year. The PKK is designated as a terrorist group by Turkey, the United States and the European Union.
Prime Minister Ahmet Davutoglu said this week Ankara aimed to prevent the PKK "spreading the fire" from Syria and Iraq to Turkey by imposing control in towns, like the army has done in mountainous areas where the militants were active in the past.
Figen Yuksekdag, co-leader of the HDP has said 200,000 people have been displaced in recent months as a result of conflict in the southeast, accusing the state of conducting a war against Kurds.
Davutoglu was reported on Thursday by Milliyet newspaper as telling reporters operations were launched to frustrate moves to trigger a civil war, accusing the HDP, whose core support is sympathetic to the PKK, of acting arrogantly after winning 13 percent of votes in a June election.
"If we had delayed a bit more (in launching operations), their intention was to launch a much more comprehensive civil war," he said, accusing the HDP leaders of "playing with fire".
Additional reporting by Gulsen Solaker in Ankara; Writing by Daren Butler; Editing by David Dolan and Dominic Evans