News Analysis: Terror threat spirals upward as crackdown on outlawed PKK intensifies

As Turkey intensified military offensive against the outlawed Kurdish Workers' Party (PKK), the nation's capital has been hit with three deadly bombing attacks since October 2015.

Analysts believe the PKK has been trying to escalate the violence in the cities, especially in central and western provinces, to force the government to ease up on the crackdown and push for resumption of the peace talks.

Sunday's car bombing attack in the heart of Ankara killed at least 37 people and wounded more than 120 others, with 15 remaining in critical condition in intensive care units in hospitals.

The attack directs to the PKK as the main culprit given that one of the two suspected bombers was identified as its militants.

"The PKK has been squeezed out in the southeastern provinces where the Turkish military has ramped up security operations to sweep PKK stronghold cities and towns," Bayram Kaya, an Ankara-based security expert, told Xinhua.

"The terror group is sending a message to the Turkish government that it will spread the violence to the west of the country including the nation's capital," he added.

Turkish Prime Minister Ahmet Davutoglu said on Monday evidence strongly suggested that the perpetrators are from the separatist PKK.

He noted 11 suspects have been detained over connection with the Ankara bomb attack.

The blast was triggered by a bomb-laden stolen vehicle in a crowded area of the city near subway and bus stations on Sunday evening, deliberately designed to cause maximum civilian causality.

The site is also close to government buildings, the Supreme Court and diplomatic missions in the downtown area where security is supposed to be intense and tight.

The government has vowed not to give in to terror, as President Recep Tayyip Erdogan said "Turkey will continue its determined fight against terrorism."

"Terror attacks do not diminish our will to fight against terror, but further boost it," he added.

On Monday, nine Turkish F-16 and two F-4 fighter jets hit 18 PKK targets in Qandil and Gara regions in northern Iraq.

Sunday's attack is the third major terror incident in Ankara in less than five months.

On Feb. 17, a suicide car bomb attack struck military transport buses in the city, killing 29 people. A PKK offshoot called the Kurdistan Freedom Falcons (TAK) claimed it.

Another suicide bombing took place on Oct. 10, 2015, when suspected Islamic State (IS) militants targeted a peace rally in Ankara, killing 103 people.

"The increase in the number of terrorist attacks in Turkey, especially in Ankara, puts the government in a more difficult position," Murat Yetkin, a Turkish analyst, believed.

Recalling that Turkish leaders have been busy in convening security meetings after each incident, he said "people are waiting for those meetings to produce more security."

Turkish opposition parties have all condemned the Sunday's deadly attack but criticized the government for the failure to provide security for citizens.

The main opposition Republican People's Party leader Kemal Kilicdaroglu asked the prime minister to sack ministers who are in charge of the nation's security.

"Turkey has been experiencing one of its deepest crises in its history. It is a crisis of governance," he said.

The Nationalist Movement Party leader, Devlet Bahceli, said the national security of Turkey is giving red alarms. "The government must not allow any vulnerability and negligence," he noted.

The PKK is listed as terrorist organization by Turkey, the United States and the European Union. It resumed violence against the government in the summer of 2015, prompting the security services to launch an offensive.

The Turkish security forces have intensified the battle against the PKK in the southeast since December. The Turkish military announced on Monday to have killed 15 PKK militants in Nusaybin town of southeastern province of Mardin, and in Yuksekova town of southeastern province of Sirnak. Endit