11/12/2016 9:22 PM AEDT | Updated 11/12/2016 9:24 PM AEDT

Turkey Death Toll Rises As Day Of Mourning Declared

Forensic officers work as emergency officers walk with bodybags on the roof of the Vodafone Arena stadium at the site where a car bomb exploded killing 38" data-caption="Forensic officers work as emergency officers walk with bodybags on the roof of the Vodafone Arena stadium at the site where a car bomb exploded killing 38" data-credit="OZAN KOSE via Getty Images">

The death toll following twin blasts in Istanbul has risen to 38, officials said on Sunday, as a national day of mourning was declared.

Turkey's Interior Minister Suleyman Soylu said the figure included 30 police officers, seven civilians and one more person whose identity had yet to be determined.

Fourteen of the 166 wounded remained in intensive care, Soylu said, adding that a total of 13 suspects had been detained in connection with the "terrorist attack" on Saturday night.

The explosions, triggered by a car and suicide bomb less than one minute apart, struck outside Beskitas's stadium less than two hours after a match had finished.

Prime Minister Binali Yildirim ordered flags to fly at half-staff Sunday across the country and at Turkey's foreign missions following the attack which occurred near a football stadium.

There was no immediate claim of responsibility but one official 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.

The civilian death toll was lower because fans had already left the newly built Vodafone Arena Stadium after the football match when the blasts occurred. Witnesses also heard gunfire after the explosions.

"We have once again witnessed tonight in Istanbul the ugly face of terror which tramples on every value and decency," Turkish President Recep Tayyip Erdogan said.

The first and larger explosion took place about 7:30pm 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 and vowed the nation would overcome terrorism.

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.

Kurtulmus said a person who had been stopped in nearby Macka Park committed suicide by triggering explosives moments later.

Forensic experts in white uniforms scoured 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.

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.

Soylu acknowledged the country was struggling against "many elements" trying to compromise its fight against terrorism.

Turkey is a partner in the US-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.

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 who threaten Turkey, the United States, and global peace and stability," Price said.

The Besiktas sports club "strongly condemned" the attack and said an employee was among the fatalities, as well as a security official. 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.

EU foreign policy chief Federica Mogherini expressed the bloc's "solidarity with Turkish citizens."

The US Consulate General in Istanbul urged its citizens to avoid the area in Istanbul, which is also home to a Ritz Carlton hotel.

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."