PAOK president Ivan Savvidis marched onto the pitch, with images showing him apparently carrying a gun in a hip holster.

On Monday afternoon, Greece's deputy minister for sports Giorgos Vassiliadis announced that the Superleague has been suspended.

"We are going for an indefinite suspension," Vassiliadis told reporters in Greece.

"We are expecting a new set of stricter rules for soccer, after spending three years trying to clean the game up.

"We will not restart unless there is a new clear framework with terms and rules agreed by everyone and care will be taken to ensure that the national team's playing obligations are not undermined."

Vassiliadis was speaking after meeting Prime Minister Alexis Tsipras at the Maximos Mansion in Athens.

He said the government is in negotiations with the local and international football authorities to agree on a new set of rules and conditions.

"Everything is on the table and in the coming hours we will make our contacts with everyone," said Vassiliadis.

"We are expecting the proposals from the federations."

An earlier PAOK statement read: "After what happened in Toumba Stadium, PAOK FC president Ivan Savvidis is preparing to take all necessary steps to protect the club and all his executives and associates from the threats and attacks they are suffering."

Greek football has been blighted by crowd trouble in recent times, and last month PAOK's league game with Olympiacos was abandoned before a ball was kicked.

Olympiacos coach Oscar Garcia, the former Brighton and Watford boss, was hit by an object thrown from the crowd, which was reported to be a toilet roll.

PAOK are third in Greece's top division and could have moved within two points of leaders AEK with a win.

The two sides could meet again in the Greek Cup final, but Vassiliadis did not specify whether that competition is also to be suspended.

- PA