World Cup 2018: Serbia chief accuses Fifa of 'brutal robbery' after Swiss defeat
The head of the Serbian Football Association has accused governing body Fifa of showing bias against his country at the World Cup in Russia.
Slavisa Kokeza says Serbia were victims of a "brutal robbery" during Friday's loss to Switzerland, accusing Fifa of "directing" officials to work against them.
"We will send a protest to Fifa today," Kokeza told the BBC on Saturday.
A Fifa spokesman confirmed a letter of protest had been received but that no further comment would be made.
Kokeza was unhappy a German referee had been appointed for a game involving Switzerland, claiming the move influenced some decisions, most notably the failure of the match official and video assistant referee (VAR) to award a penalty when Aleksandar Mitrovic was wrestled to the ground by two Swiss players.
"I do not think this is only about VAR, but that the whole thing was directed by the people who appoint referees," Kokeza said.
"We all know too well that more than half of Switzerland's population is German.
"Technical staff, players, people in Serbia, they are all disappointed and frustrated because of injustice some people at Fifa came up with."
Asked how he wanted Fifa to respond, he replied: "It is clear to Europe and the world that Serbia was brutally robbed. I do not expect Fifa to take action in order for this brutal robbery not to happen again, because, I repeat, it was all directed."
Kokeza also criticised the 'double eagle' celebration given by Switzerland's two ethnic Albanian goalscorers during Friday's match, describing the actions as "scandalous and shameful".
Granit Xhaka and Xherdan Shaqiri made the gesture, which is a nationalist symbol representing the double-headed eagle on Albania's national flag.
Both players' families are from Kosovo, where a Serbian crackdown on the Albanian population only ended with Nato military intervention in 1999.
Shaqiri also wears boots displaying the Swiss flag on one heel and the Kosovan flag on the other.
"It deserves to be condemned by the whole football world," Kokeza added. "It was not the only provocation by the Swiss players. One sufficient detail was the football boots of one of their players - the boots had a flag of a non-existing country displayed on them.
"We expect Fifa to impose sanctions against the players who acted against rules of Fifa and fair play, as well as against the national association of the country they play for."
Fifa confirmed on Saturday that disciplinary proceedings had been opened against Xhaka and Shaqiri, as well as the Serbian FA for the conduct of their fans, and Serbia head coach Mladen Krstajic for alleged statements made in the aftermath.