Thirty policemen and seven civilians were among the dead in the twin attacks outside a soccer stadium in the heart of Istanbul.
The death toll from twin bombings outside the Besiktas football stadium in central Istanbul on Saturday has risen to 38, Turkish Interior Minister Suleyman Soylu said on Sunday.
Thirty policemen, seven civilians and an unidentified person were killed in two blasts near the stadium of top division team Besiktas, two hours after a match ended.
Turkey's Deputy Prime Minister Numan Kurtulmus said a car bomb was remotely detonated outside the stadium and 45 seconds later, a suicide bomber triggered his device at a park near the Vodafone Arena.
So far arrested 13 people and authorities suspect the attack was carried out by the PKK, who are considered a terror organisation by the US, EU and Turkey.
Kurtulmus told CNN Turk "arrows point" to the PKK.
A day of national mourning has been declared in Turkey and flags are flying at half mast.
President Recep Tayyip Erdogan cancelled a state visit to Kazakhstan to deal with the issue.
"A terrorist attack has been carried out against our security forces and our citizens. It has been understood that the explosions after the Besiktas-Bursaspor football game aimed to maximise casualties. As a result of these attacks unfortunately we have martyrs and wounded," Erdogan said shortly after the attack.
Besiktas football club had earlier tweeted on their official account that a police chief and congress member from the club, Vefa Karakurdu, was killed along with Tunc Uncu, a 29-year-old staff member who worked at the stadium's merchandise store.
Kongre yemiz Vefa Karakurdu, Terr Saldrsnda ehit Olduhttps://t.co/73USCWWHZ5 pic.twitter.com/nttQvowDw8— Beikta JK (@Besiktas) December 11, 2016
Kartal Yuvas alanmz Tun Uncu, Terr Saldrsnda ehit Olduhttps://t.co/pZO54ItHmk pic.twitter.com/neywfi1vtK— Beikta JK (@Besiktas) December 11, 2016
The club said Karakurdu was a police chief assigned to the stadium and was responsible for security.
TRT World's Muhammad Karim captured video footage of fire trucks and ambulances rushing to the scene of the explosions.
Posted by Muhammad Karim on Saturday, December 10, 2016
The attacks happened around 10:30pm, two hours after a game ended between home side Besiktas and visitors Bursaspor.
An eyewitness told TRT World that soon after the explosions he heard gunfire.
"We felt terrible. The ground was shaking," he said, "This is the first time I saw an explosion."
TRT World's Wilson Dizard reports from the scene.
TRT World's digital reporter is at the scene of the explosions in Besiktas, Istanbul. He reports hearing 2 explosions in the area. pic.twitter.com/cI3T4FCf0t— TRT World (@trtworld) December 10, 2016