UEFA president Michel Platini on Tuesday urged Croatia and Serbia to tackle hooliganism ahead next month's high-risk World Cup qualifier between the former foes.
In letters sent separately to Zoran Milanovic and Ivica Dacic, prime ministers of Croatia and Serbia respectively, Platini also asked for an urgent meeting with European football's governing body officials over the issue.
"UEFA is extremely concerned by all forms of violence at certain matches played by Croatian clubs in UEFA competitions," Platini was quoted as saying in the letter to Milanovic, published on the Croatian Football Federation (HNS) official website.
A similar letter was also sent to Dacic, a government statement said in Belgrade.
UEFA tasked its official Frantisek Laurinec to meet top government and football officials from Croatia and Serbia in their respective countries over the issue, Platini said.
He proposed that the meeting take place in March, stressing that tackling of football violence was crucial for the future of football in the two former Yugoslav republics.
Platini has repeatedly warned Croatia and Serbia that if they do not root out violence among football supporters they risk being excluded from international competitions.
UEFA has fined the federations of two countries on several occasions for violence and racist behaviour of hardcore football fans.
The HNS and its Serbian counterpart had decided that, in a bid to avoid crowd trouble, away fans would be banned from the matches between the countries who fought a bitter war in the 1990s as the former Yugoslavia fell apart.
Croatia faces Serbia on March 22 in Zagreb, while the return match is to be played on September 6 in Belgrade.