An investigation has been launched after Ireland's Rugby League team's game against Serbia on Saturday had to be abandoned following a brawl.
The disturbances reportedly broke out in the Belgrade game after a Serbian team official struck an Ireland player.
Four players are believed to have been sent off before the brawl which led the Irish to walk off the field even though they were 24-16 ahead.
There were also reports that an Ireland player was kicked in the head.
Rugby League's European Federation said on Sunday that a "full investigation" had been launched into the abandoned match.
"We are collecting formal statements from both Federations as well as the match commissioner, the officials and independent observers and reviewing the match footage. A further will be issued in due course," said Rugby League European Federation's general manager Danny Kazandjian.
In live postings on its official Facebook page during Saturday's international in the Makis Stadium, Rugby League Ireland alleged that a Serbian team member had kicked one of the Ireland players in the head during the mass brawl.
Despite the incidents, the Ireland players were reported to have sustained no serious injuries.
On Sunday, Rugby League Ireland released a short statement said that the European federation was investigating the incidents.
The match was being staged as part of Rugby League's 120th anniversary celebrations.