Poland prime minister Mateusz Morawiecki has ordered “urgent diplomatic action” after two Legia Warsaw players were arrested following their Europa Conference League defeat away at AZ Alkmaar on Thursday.
Radovan Pankov and Josue Pesqueira were taken off the team bus by Dutch police after an altercation with security and remain in the Netherlands.
“I have instructed the Polish foreign ministry to take urgent diplomatic action to verify the events of the night,” said Morawiecki.
“Polish players and fans must be treated in accordance with the law. There is no consent to breaking it.”
Legia president Dariusz Mioduski says he was hit while trying to mediate, with police reportedly refusing to let the team bus leave the stadium until Portuguese midfielder Josue and Serbian defender Pankov had been detained.
Dutch police have confirmed a 28-year-old man from Serbia and a 33-year-old from Portugal were arrested after the match on a charge of mishandling. The Polish side described the events after the game as “scandalous” and said Mioduski will hold a news conference at the club's stadium at 14:00 local time (13:00 BST) on Friday.
Earlier, riot police had been deployed before kick-off when a group of Legia fans stormed an entrance gate.
“One riot police officer became unconscious during that action. After treatment, this colleague was unable to continue working,” read a Dutch police statement.
“Tear gas was used to protect their own safety and that of the stewards. Legia supporters also took away a number of batons and pepper spray from riot police. It meant that a number of away fans entered the visitors' section without a ticket or having their tickets checked.”
During the day police declared the area around Alkmaar station and the stadium a safety risk and carried out preventative searches of Legia fans following reports some were in possession of fireworks.
AZ Alkmaar were fined fined 80,000 euros (£68,670) by European governing body Uefa in July over the behaviour of their fans during their Europa Conference League semi-final second leg match against West Ham in May. AZ fans attacked an area in which West Ham players' friends and family were seated, with players subsequently trying to intervene to protect them.
‘The Polish government has long courted football supporters' – analysis
Adam Easton, BBC Warsaw Correspondent
Reports in the Polish media about the incident have been routinely described as a “scandal” even by those outlets which don't support the government. For Poland's populist right-wing government, it's important to be seen to be reacting firmly to alleged injustice towards players from the 15-times Polish champions Legia Warsaw.
That's because the government is seeking an unprecedented third consecutive term in office in elections in nine days' time and is afraid of losing votes to a small far-right challenger, Konfederacja. The government has long courted football supporters, unlike the main opposition grouping which clamped down on ultras when it was in office before Poland co-hosted Euro 2012 with Ukraine.
Legia is one of the biggest clubs in the country. Last season, the club averaged more than 21,000 spectators at home matches, the highest attendance in the Polish top-tier Ekstraklasa despite not having the biggest ground.
— CutC by bbc.com
