A planned "moment of silence" for victims of the Paris massacre was suddenly interrupted by loud boos and apparent cries of "Allahu Akbar" ("God is great") from soccer fans at a stadium in Turkey Tuesday.

"Our fans should have behaved," Turkish manager Fatih Terim said after the friendly match against Greece. Organizers of other soccer matches across Europe held their own moments of silence with more cooperation.

It was unclear whether any of the Turkish fans were intentionally supporting ISIS or the attackers. The moment of silence was supposed to last for one minute.

Some witnesses wrote on social media that it was meant as a protest of Western hypocrisy. They cited a suicide bombing at a peace rally in Ankara that killed more than 100 people in October. ISIS claimed credit for that attack, which received less of a global outpouring of support for victims.

Other soccer fans said it was rare to hear complete silence during "moments of silence" at the stadium in Istanbul.

A sell-out crowd of nearly 17,000 packed the stadium. The Turkish and Greek Prime Ministers Ahmet Davutoglu and Alexis Tsipras watched the game together in a sign of unity despite recent tensions between the two neighbors over issues including the refugee crisis.

The game ended in a draw, 0-0.