Russia issues security guarantee to Arsenal fans

Moscow on Saturday announced the expulsion of 23 British diplomats in a tit-for-tar response to London's "provocative" measures over the nerve agent attack on Sergei Skripal and his daughter in England.

Britain issued a travel warning to people in or planning to travel to Russia after expelling the same number of Moscow diplomats on Wednesday.

And Foreign Secretary Boris Johnson on Friday said it was "overwhelmingly likely" that Russian President Vladimir Putin personally ordered the attack.

The Kremlin called his comments "shocking and unforgivable".

All of which has left Arsenal fans alarmed about the prospects of playing CSKA in Moscow on April 12 for the second leg of their Europe League quarter-final.

One Arsenal supporters' group called it "a hot potato of a draw in view of the political stand-off".

The club itself reposted on its website a Foreign Office travel advisory warning of possible "anti-British sentiment or harassment".

Russia's World Cup organising committee chief Alexei Sorokin expressed disappointment about the tensions and said Arsenal fans have nothing to fear.

"It is a shame that the games will be played in such circumstance," said Sorokin, who is also a senior member of the Russian Football Union.

"We will ensure security in equal measures to all -- from dignitaries to fans," Sorokin told TASS.

But he also expressed a hint of annoyance at Arsenal's decision to put up the Foreign Office travel advisory after Friday's Europa League draw.

"To us, there is no difference which country people come from or what our diplomatic relations with them are," he said.

"There are absolutely no grounds for such warnings."

Sorokin has been fighting an uphill battle to clean up Russia's image ahead of its first World Cup at home.

The June 14 to July 15 tournament has been associated closely with Vladimir Putin ever since the Russian strongman wrested the hosting rights away from England in 2010.

Organisers are keen to resolve all the controversies and the poisoning case does not help.

Preparations have already been shadowed by concerns ranging from racism to hooliganism and doping that saw Russia perform at the Pyeongchang Winter Games under a neutral Olympic flag.

British Prime Minister Theresa May decided to give the World Cup itself a snub by announcing that royals and ministers would not be attending.

A boycott by the England team is thought unlikely despite wide-ranging speculations about it in the media and support from some British MPs.