The UK and US embassies in Russia have warned that a terrorist attack could take place in Moscow within the next 24 hours.

The security alert, issued by the US embassy and repeated by the UK, urged American citizens to “avoid large gatherings over the next 48 hours”.

The embassy said it is “monitoring reports that extremists have imminent plans to target large gatherings in Moscow, to include concerts,” but it did not specify what kind of threats it referred to, or who might be behind them.

Russia’s Federal Security Service (FSB) said on March 7 that its agents had thwarted a potential Islamic State terrorist attack on a Moscow synagogue, with state-owned media reporting the militants behind the plot were killed. It is not known if the incidents are related.

The embassy also advised its citizens to “monitor local media for updates” and “be aware of your surroundings”.

Follow the latest updates below