Two explosions outside a major soccer stadium in central Istanbul on Saturday killed least 29 people and wounded more than a hundred others, a report said.

Witnesses heard gunfire after the explosions, which apparently targeted police officers, who cordoned off the area as smoke rose from behind the newly built Vodafone Arena Stadium, reported the Wall Street Journal.

“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 in a statement.

There was no immediate claim of responsibility for the attack, which wounded 166 people. Among the fatalities were 27 police officers, Interior Minister Suleyman Soylu was quoted as saying in the report.

The minister said 10 people had been arrested in connection with the attacks.