A car bomb followed by a suicide bombing left 29 people dead and 166 wounded Saturday night outside a soccer stadium in central Istanbul.

Authorities said that a car bomb detonated by remote control was followed 45 seconds later by a suicide bomber. All but two of those killed were police officers, authorities said. 

Turkish Interior Minister Suleyman Soylu was quoted as saying the attack was a “cruel plot.” He also said 17 of the wounded were undergoing surgery and another six were in intensive care.

In photographs, smoke was seen rising from behind the newly built Vodafone Arena Stadium, known as Besiktas Stadium, after the local team and neighborhood. Dozens of ambulances were parked in the nearby area to care for the wounded. 

The blasts struck hours after the end of a match between two of Turkey’s top teams.

The first and larger explosion took place about 10:30 p.m. after the home team Besiktas beat visitor Bursaspor 2-1 in the Turkish Super League. Officials gave no immediate details on the nature of the second explosion, which sounded like it came from the same area.

“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,” Turkish President Tayyip Erdogan said in a statement.

There was no immediate claim of responsibility. But officials said that at least 10 people have already been detained in connection with the attack. Istanbul has been the site of attacks attributed to ISIS and also to Kurdish militants in the last year. 

“It is thought to be a car bomb at a point where our special forces police were located, right after the match at the exit where Bursaspor fans exited, after the fans had left,” the Associated Press quoted Soylu as informing Turkey’s state-run Anadolu Agency. “We have no information on the number of dead. God willing we hope there won’t be any. The wounded are police.”

Turkish Transport Minister Ahmet Arslan called the attack an act of terrorism on Twitter, Reuters reported. 

Armed police sealed off streets around the Vodafone Arena, home to the Besiktas soccer team.

Besiktas beat visitor Bursaspor 2-1 in the Turkish Super League.

Bursaspor said none of the wounded were fans and issued a statement saying “we wish a speedy recovery to our wounded citizens.”

Witnesses said police were deployed and had cordoned off the area as smoke rose from the newly built stadium.

They said gunfire could be heard in what appeared to have been an armed attack on police.

Images broadcast on television showed more than a dozen ambulances on a street hugging the stadium and a police helicopter flying overhead with its search lights on.

Prime Minister Binali Yildirim and Istanbul Governor Vasip Sahin had been notified, the agency said.

The Associated Press contributed to this report.