World Cup 2018: Russian stadium's shaking pitch concerns Fifa
Fifa has expressed its concerns over a shaking pitch at one of Russia's 2018 World Cup venues.
The £550m 68,000-seater stadium in St Petersburg has a retractable playing surface which world football's governing body says is unstable.
It added: "Engineers will propose a solution to ensure a stable field."
The Krestovsky Stadium, which will become the home of Zenit St Petersburg, will host a World Cup semi-final and 2017 Confederations Cup games.
Russia's deputy prime minister Vitaly Mutko said: "The issue is that the field rolls into the venue on an unstable base and needs to be strengthened."
He said the problem was "nothing unusual" and the stadium would still meet its completion date next month.
Russia MP and former USSR player Valery Gazzaev added: "If the pitch is unsuited to holding such major events, then why has it been built?"
Russian opposition blogger Rustem Adagamov wrote on Twitter: "Just what we need, to spend 10 years building a stadium, spend half a billion dollars, and build a pitch you can't play on. Awesome."
Additional information provided by BBC Monitoring