Turkish troops killed 21 terrorists in clashes in southeastern Turkey near the Iraqi border on Wednesday, security sources said. At least 100 PKK terrorists were believed to have taken part in the attacks, which targeted eight locations. Turkish commandos reportedly crossed the border into northern Iraq in pursuit of the terrorists after the attack, which occurred in the early morning hours of Wednesday.

There were reportedly intermittent clashes between the troops, who advanced some three to four kilometers into Iraqi territory and the PKK terrorists in the border area near Çukurca in Hakkari province. PKK members have been using Iraq as a launching pad for attacks on Turkish targets in a war for autonomy in Turkey´s Southeast.

The private Cihan news agency says Turkish warplanes that took off from Diyarbakır are striking PKK bases in northern Iraq. Turkey´s Parliament recently passed a bill extending permission, as it has done several times since 2007, for the Turkish military to mount cross-border operations against members of the PKK in northern Iraq in the coming year. Turkish air and artillery operations against suspected PKK members in the Kandil Mountains have intensified since August. The strikes were ordered after a break of more than a year in retaliation for an increase in PKK attacks on security forces inside Turkey. In the early morning hours of Wednesday terrorists attacked several military and police buildings in Çukurca and Hakkari´s city center. Twenty-four soldiers and police officers were killed. Another 18 soldiers were wounded when the terrorists opened fire on military outposts in Çukurca and Yüksekova near the border with Iraq. The attacks occurred simultaneously.

It was the deadliest PKK attack in 18 years. It was the fourth deadliest attack since the PKK started its campaign of separatist violence nearly three decades ago.

The attacks come only a day after five policemen and four civilians, including a 2-year-old and a 10-year-old, were killed by a roadside bomb planted by the PKK in nearby Bitlis province. Wednesday’s attacks also come only days after Turkish President Abdullah Gül visited troops in the region to boost morale in an area that has seen increased violence in recent months.

Chief of General Staff Gen. Necdet Özel and force commanders travelled to Hakkari after the news of the soldiers’ deaths. Prime Minister Recep Tayyip Erdoğan, who was scheduled to leave the country on Wednesday for an official visit to Kazakhstan, cancelled his trip. There are reports that Erdoğan will also go to Hakkari.

Erdoğan called an emergency meeting at the Prime Ministry after the attacks. Deputy Prime Minister Bekir Bozdağ, Interior Minister İdris Naim Şahim, Defense Minister İsmet Yılmaz and National Intelligence Organization (MİT) Undersecretary Hakan Fidan are attending the meeting. Turkey’s top officials cancelled their travel plans to attend the emergency meeting.

Turkey’s Foreign Minister Ahmet Davutoğlu also cancelled a planned trip to Serbia on Wednesday, while Finance Minister Mehmet Şimşek cancelled a scheduled trip to the US. Arınç, who was on a visit to Macedonia, cut his trip short and returned to Ankara, the Anatolia news agency reported on Wednesday. Science, Industry and Technology Minister Nihat Ergün was also among the ministers canceling trips and communicating with the government in Ankara as he cancelled a visit to the European Organization for Nuclear Research (CERN) in Switzerland, scheduled for Thursday and Friday. Although Turkish EU Affairs Minister and chief negotiator Egemen Bağış was not at Wednesday’s emergency meeting, he called off a trip to the Central Anatolian province of Eskişehir, where he was set to attend a meeting on the province’s EU progress, and met instead with the head of the EU Delegation to Turkey, Ambassador Marc Pierini. The details of the meeting were not made public, but Bağış was expected to discuss Turkey’s concerns over the funding the PKK is receiving from sources within EU member countries.

Parliament on Thursday will hold an emergency session to discuss new measures against the PKK, Deputy Prime Minister Bozdağ announced after Wednesday’s terrorism summit.

PKK terrorist activities have been a central concern for Turkish governments since the organization took up arms in 1984 and waged a bloody war for autonomy, which has cost more than 40,000 lives in almost three decades. Despite fitful cease-fires, the terrorist organization organizes attacks from its bases in northern Iraq and as of July stepped up its attacks, which have claimed the lives of dozens of security personnel as well many civilians.