ISTANBUL (AP) Turkey declared a national day of mourning and began to bury its dead Sunday after twin blasts in Istanbul killed 38 people and wounded 155 others near a soccer stadium. It was the latest large-scale assault to traumatize a nation confronting an array of security threats.
The bombs Saturday night targeted police officers, killing 30 of them along with seven civilians and an unidentified person, Turkish Interior Minister Suleyman Soylu told reporters Sunday. He said 13 people had been arrested in connection with the ''terrorist attack.''
President Recep Tayyip Erdogan vowed that Turkey would overcome terrorism while Prime Minister Binali Yildirim ordered flags to fly at half-staff Sunday across the country and at Turkey's foreign missions.
''We have once again witnessed tonight in Istanbul the ugly face of terror, which tramples on every value and decency,'' Erdogan said.
There was no immediate claim of responsibility for the attack but two officials said suspicions were focused on Kurdish militants.
Deputy Prime Minister Numan Kurtulmus told the private news channel CNN Turk that ''arrows point to the PKK.'' He was referring to the outlawed Kurdistan Workers' Party, which has waged a decades-long insurgency. That preliminary assessment was echoed by the interior minister.
The first and larger explosion took place about 7:30 p.m. Saturday after the home team Besiktas beat visitor Bursaspor 2-1 in the Turkish Super League. Erdogan said the timing of the attack aimed to maximize the loss of life.
Soylu said the first explosion was caused by a passing vehicle that detonated in an area where police special forces were located at the stadium exit. A riot police bus appears to have been the target.
Moment later, a person who had been stopped in nearby Macka Park committed suicide by triggering explosives, according to the minister.
The civilian death toll was lower because fans had already left the newly built Vodafone Arena Stadium after the soccer match when the blasts occurred. Witnesses also heard gunfire after the explosions.
Soylu said 136 people remained hospitalized Sunday after the attack, including 14 under intensive care.
Forensic experts in white uniforms worked overnight, scouring the vicinity of the stadium and the vast park where the suicide bombing took place. Glass from the blown-out windows of nearby buildings littered the pavement.
Authorities have determined that about 300-400 kilograms of explosives were used in the attack, Kurtulmus told CNN Turk.
Vehicle and pedestrian traffic tentatively resumed Sunday in the blast area, which municipal workers rushed to clean up.
At noon, to the mournful sound of trumpets, funeral services were held at Istanbul's police headquarters for some of the slain police officers with the country's top brass in attendance. Their comrades solemnly carried the coffins, which were draped in the Turkish flag, as mourners wept.
This year Istanbul has witnessed a spate of attacks attributed by authorities to the Islamic State group or claimed by Kurdish militants. A state of emergency is in force following a failed July 15 coup attempt.
Saturday's incident marked one of the bloodiest to hit the bustling city at the crossroads of Europe and Asia. A triple suicide-and-gun attack on the city's Ataturk Airport in June killed 44 people and wounded scores of others. Kurdish-linked militants have claimed other deadly attacks in Ankara, Istanbul and areas of the southeast.
The steady stream of violence has delivered a bitter blow to Turkey's tourism sector, a mainstay of the country's economy. Soylu acknowledged the country was struggling against ''many elements'' trying to compromise its fight against terrorism.
Turkey is a partner in the U.S.-led coalition against the Islamic State and its armed forces are active in neighboring Syria and Iraq. It is also facing a renewed conflict with an outlawed Kurdish movement in the southeast.
Condemnations of the attack came from a range of Turkish politicians, sports leaders and clubs and U.S. and EU officials.
Turkey's pro-Kurdish People Democratic Party, or HDP, issued a statement ''strongly condemning'' the attacks and saying it ''felt great sadness and shared in the sorrow.''
Turkish authorities, particularly the president, have routinely accused the party of being linked to the PKK and backing terrorism. The party, which had both of its leaders detained in terror probes and multiple elected officials arrested or removed from public service in the southeast, denies the charge.
The chair of the main opposition Republican People's Party also condemned the attack.
Ned Price, a spokesman for the White House National Security Council, said Washington condemned the attack in ''the strongest terms.''
''We stand together with Turkey, our NATO Ally, against all terrorists,'' Price said.
The Besiktas sports club ''strongly condemned'' the attack and said a store employee and a security official were among the fatalities. Bursaspor issued a statement wishing ''a speedy recovery to our wounded citizens.''
Aleksander Ceferin, president of European soccer's governing body UEFA, and European Union Enlargement Commissioner Johannes Hahn also condemned the attack.
''Violence has no place in a democratic society,'' Hahn wrote on Twitter.
The U.S. Consulate General in Istanbul urged its citizens to avoid the area in Istanbul.
Turkey's radio and television board issued a temporary coverage ban citing national security concerns. It said ''to avoid broadcasts that can result in public fear, panic or chaos, or that will serve the aims of terrorist organizations.''
Cinar Kiper and Bulut Emiroglu in Istanbul contributed.