Moscow has told Britain it must cut just over 50 more of its diplomatic and technical staff in Russia as a standoff deepened over the poisoning of a Russian former spy and his daughter in England, the Russian Foreign Ministry said on Saturday.
Moscow also demanded an official explanation for the search of a Russian passenger plane in London, saying it reserved the right to act similarly against British airlines in Russia. Britain said the search was routine.
Russia advised its citizens to think carefully before traveling to Britain, warning they could fall victim to official harassment.
More than 100 Russian diplomats have been expelled by Western countries, including 23 from Britain, to punish the Kremlin over the March 4 attack on Sergei Skripal and his daughter Yulia in the historic English city of Salisbury.