The Greek soccer league game between Panathinaikos and Olympiakos Pireaus had to be abandoned on Sunday after home-team fans set fire to several parts of the stadium, according to Reuters.

The Athens derby was called off with nine minutes remaining as conditions became unsafe for all involved after a number of explosions occurred close to the field of play.

Despite visiting-team fans being barred from the stadium under Greek league rules, due to the threat of violence, clashes between home fans and the police began before kickoff. Hundreds of young people without tickets tried to force their way past police into the stadium, according to Sports Illustrated.

The second half of the contest was then delayed by close to an hour as fans attacked police with flares, missiles, and Molotov cocktails, Reuters reported.

The tension inside the Olympic Stadium only deepened when Olympiakos, four points ahead of their great rivals before the game, took the lead in the 51st minute through Djamel Abdoun.

Seats inside the stadium, as well as the scoreboard were set ablaze, according to Sports Illustrated.

Twenty police officers were injured and more than 50 arrests were made, according to police, Reuters said.

Panathinaikos captain Kostas Katsouranis later explained his distaste at the events to reporters.

That was not football, Katsouranis said, according to Reuters. Certainly it's one of the worst moments in Greek football, and I don't even want to comment on the game. As a team, we will just try to get on with the next matches and fight for a place in the Champions League qualifiers.

This incident is far from the first occurrence of fan violence in Greek soccer. Just over a year ago, Olympiakos fans stormed the pitch after a victory over Panathinaikos, tearing down goals and launching fireballs in front of police.

Then-Panathinaikos striker Djibril Cisse was also attacked by rival fans, prompting the French striker to announce he wanted to leave the club, according to AFP,