Six people have been arrested for the pitch invasion that followed Espanyol's defeat to Barcelona at the end of last season, local police have announced.
The arrestees are all men aged between 23 and 46 and have been charged with causing damages worth over €30,000 ($31,930) to the RCDE Stadium.
Police say the investigation is ongoing and are not ruling out further arrests in the coming days.
Barça's 4-2 win at Espanyol in May secured the LaLiga title for Xavi Hernandez's side while simultaneously relegating their local rivals into the second tier of Spanish football.
At full-time, as Barça's players celebrated winning the league for the first time since 2019, hundreds of supporters managed to get on to the pitch and chase them down the tunnel.
"Supporters from the most radical section [of the stadium], the majority with their faces covered, breached the safety ring to invade the pitch and impede the celebration of the Barcelona players," Catalan police said in a statement Friday.
"During the incidents, no member of the Barça squad or staff had any contract with those who had violently entered the pitch thanks to the quick intervention from the police and the private security team.
"However, many of the pitch invaders had confronted security staff, thrown objects and caused significant damage to the stadium and to a journalist's camera."
Espanyol were originally ordered to play their first two games of this season behind closed doors, although that was reduced to one match on appeal in addition to a €25,000 fine.
After charging at the Barça players, Espanyol fans turned their attention to the directors' box and demanded president Chen Yansheng's resignation.
The mood against the club's owner has soured in recent years following two separate relegations from LaLiga.
Espanyol secured an immediate return to the top-flight after dropping into the second division in 2020 but, after two years back among the elite, they were relegated again last season.
After 13 games this year, they sit fourth in the Spanish second division with 23 points, five behind early leaders Leganés.