Turkish police on Monday detained four suspects near the Syria border they believe are linked to the deadly bomb attack in the heart of the capital, according to local media.
Police acted on the tip-off that the car that exploded in Ankara had been bought from a dealership in Sanliurfa, state-run Anatolia news agency reported. The four suspects were due to be taken to Ankara, the agency said.
Turkish warplanes on Monday struck Kurdish rebel bases in northern Iraq after the deadly bomb attack that killed at least 36 people, the army said.
The fighter jets hit arms depots and shelters of the outlawed Kurdistan Workers' Party (PKK) in the mountainous Kandil and Gara regions in northern Iraq, the army said.
Three more people succumbed to injuries following the suicide car bomb in the heart of the Turkish capital, bringing the overall number of victims to 36, a minister said Monday.
"As of this morning... we lost three more citizens in hospital," Health Minister Mehmet Muezzinoglu said in televised comments.
The body of one attacker had been found, he said, indicating that there might have been two.
The attack -- the third to strike Ankara in five months -- targeted a busy transport hub on Sunday which is close to the prime minister's office and the parliament.
"I curse that mindset which dares to massacre innocent civilians," Muezzinoglu said, warning that Turkey would wipe out all terrorists on its soil.
Police cordoned off the scene and put up barriers which made visibility impossible on Monday morning, an AFP correspondent reported.
Barricades were put up around 200 meters from the scene as police patrolled the area and forensic teams continuing their investigation.
Turkish authorities enforced a total blackout of media reports from the scene, local media said. A Turkish court also banned access to Facebook and Twitter in the country over the spread of photos of victims strewn across Ankara's streets spreading over the social media sites.
A security official told AFP that initial findings showed the blast was a suicide attack.
The fact that militants were able to strike again so soon in an area close to the prime minister's office, parliament building and foreign embassies will raise fresh questions about Turkey's ability to manage the twin security threat posed by the Islamic State group (IS) and Kurdish rebels.
Israeli Prime Minister Benjamin Netanyahu released a statement expressing sympathy over the attack.
"Israel expresses sympathy to the Turkish people in its war against terror and calls on the international community to unite in the fight against terror," a statement read.
It was the first condemnation of a terror attack in Turkey to come from Israel in a long time, reflecting warming relations between the countries.
Also in the aftermath of the blast, Prime Minister Ahmet Davutoglu, who was was scheduled to travel to Jordan on Tuesday, postponed his trip to a later date.
President Recep Tayyip Erdogan said the government would "never abandon its right to legitimate defense against the terrorist menace."
Erdogan's first move following the attack was blocking the two popular social media websites, Facebook and Twitter, as well as banning "some" local media from covering the blast, the Independent reported.
The explosion comes just weeks after almost 30 people were killed in a car bomb attack targeting the military in the city on February 18.
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Turkey has been on high alert following a string of deadly attacks since the middle of last year, most of them blamed on the IS group, including a double suicide bombing in Ankara in October that left 103 people dead.
As recently as Friday, the US embassy issued a warning about a possible plot to attack part of central Ankara, advising American citizens they should avoid the area.
Sunday's blast comes at a delicate moment for Turkey, as it seeks to persuade the European Union to speed up its path to membership of the bloc in return for help with the migrant crisis.
The Kurdistan Freedom Falcons (TAK), linked to the PKK, said it carried out the February bombing in Ankara as revenge for operations by the Turkish military in the southeast of the country and warned foreign tourists not to visit.
A two-year ceasefire between the government and Kurdish rebels collapsed in the middle of last year and since December security forces have been waging a major campaign against the PKK in the southeast of the country.
Strict 24-hour curfews were imposed in a number of Kurdish-dominated towns and cities to allow the military and police to pursue the battle against fighters who had dug trenches and put up barricades.
Sunday's attack came hours before curfews were due to take effect in two more towns in the southeast as a prelude to fresh military operations.
Authorities said restrictions would be slapped on Yuksekova, near the Iranian border, and Nusaybin, on the frontier with Syria, to "restore order and security" following an increase in "terrorist activity".
Ankara has vowed to wipe out the PKK, classed as a terrorist organisation by Turkey and its Western allies, and has said "clean-up" operations in Yuksekova, Nusaybin and Sirnak, a third Kurdish city, are imminent.
(Staff with AFP)