Two explosions near the entrance of a soccer stadium in central Istanbul on Saturday evening killed at least 29 people, most of them police officers, and injured more than 166 others, Turkey’s interior minister said.

There was no immediate claim of responsibility for the attack, which was the deadliest and most brazen in central Istanbul in months. The explosions, which could be heard across the city and sent up a plume of smoke, occurred outside the Vodafone Arena in the Beskitas area of Istanbul, less than a mile from the city’s bustling Taksim Square and on the edge of the Bosporus.

Turkey has been hit by multiple terrorist attacks in recent years, including from both the Islamic State and Kurdish militants waging a war for autonomy. In June, suspected Islamic State operatives staged an assault on Istanbul’s Ataturk Airport, killing nearly 50 people. Militants have also carried out deadly attacks in the capital, Ankara, and other Turkish cities.

Turkish Interior Minister Suleyman Soylu said the attack started with a car bomb that targeted a group of riot police posted at the stadium after a soccer match earlier Saturday evening according to local media reports. The second explosion, which authorities attribute to a suicide bomber, happened less than a minute after the first, in a throng of police officers, Soylu said.

Fires set off by the blasts could be seen burning around the stadium in footage aired on local news channels. Dozens of ambulances were seen rushing to ferry the wounded.

One of the soccer teams that had played earlier that night, Bursaspor, said on its official Twitter account that none of its fans had been injured in the bomb, which produced a massive, orange fireball and shook doors and windows in Turkey’s largest city.

A video of a news conference at the stadium showed the moment of the blast, which sent people running. Another video circulated online showed the fiery explosion in the background of two young men playing guitar on the Bosporus.

Turkey has been roiled by political instability, including a failed coup attempt against the government this summer. A widespread crackdown on suspected coup plotters has also snagged dissidents and opposition figures, including ethnic Kurdish politicians.