All top-flight soccer matches in Greece will be played without fans in the stadiums for the next two months, in the latest crackdown on supporter violence following a sport-related riot last week that left a police officer with life-threatening injuries.

The government said Monday that it would introduce emergency legislation to make the ban on supporters effective immediately. It will end on Feb. 12 with a possible extension to follow.

This past weekend's professional football matches were postponed following a series of violent incidents at matches and last week's riot that occurred outside a volleyball game believed to be led by organized soccer fan groups.

The 31-year-old police officer who was injured in the clashes remains in a coma after being hit in the left leg by a flare, causing extensive bleeding and cardiac arrest.

“This murderous attack against a policeman is not the first incident of extreme fan violence in recent years. Criminals in the guise of sports fans are committing serious offenses, seriously injuring and killing people,” government spokesman Pavlos Marinakis told reporters.

He said all 14 clubs competing in the top-flight Super League will have to install surveillance cameras inside stadiums and use personalized ticketing systems that require the holder to show identification upon entry before being allowed to admit supporters.

The security systems, including a network of high-resolution surveillance cameras inside stadiums, would have to adhere to standards set by soccer’s governing body in Europe, UEFA, Marinakis said.

An 18-year-old man has been arrested and taken into police custody in connection with the police officer’s injury to face charges of attempted murder. The man, who has not been identified, appeared at an arraignment hearing Monday after being escorted to court in handcuffs by police. He was given until Thursday to prepare his defense.

Violence has plagued Greek soccer for decades despite repeated efforts to crack down on the supporters’ associations blamed for the attacks, mostly outside stadiums.

Olympiakos, under new Portuguese head coach Carlos Carvalhal, will face Serbia’s Backa Topola in the Europa League at home Thursday without fans as a result of the decision.

But Greek clubs Panathinaikos and PAOK will conclude their European matches with fans. Panathinaikos hosts Maccabi Haifa in Athens Thursday in the Europa League and PAOK hosts HJK Helsinki in the Conference League also on Thursday in Thessaloniki.