FIFA warns Serbia over fan misbehaviour
It said Serbia had been fined for fan misbehaviour during the team's qualifiers in Austria and Romania, as well as last month's home game against France.
"We have received a very worrying note from the FIFA disciplinary committee saying that we could have points deducted if our fans keep repeating these forbidden acts," the FSS said.
Serbian fans lit dozens of flares and threw them on the pitch in matches with Austria and Romania, having also clashed with security in the latter game.
They also lit flares and set off firecrackers during the game with France.
The Serbian FA and players have appealed to fans to behave during Saturday's Group Seven home qualifier with Romania, which could seal Serbia's place in next year's finals.
"We will continue to take comprehensive action to prevent any further incidents, which are undermining our successful qualifying campaign," FSS general secretary Zoran Lakovic said.
Serbia top Group Seven with 19 points from eight matches and need one win from their last two games - against Romania and in Lithuania on Wednesday - to qualify for their first major tournament as an independent nation.