Russia has ordered the expulsion of more diplomats from Western countries in a tit-for-tat response over the poisoning of an ex-spy in the UK, the BBC reported on Friday.
The retaliatory measure comes a day after Russia kicked out 60 US diplomats and closed the St Petersburg consulate.
The UK has blamed Russia for the nerve agent attack which Russia denies.
Moscow called in the British ambassador on Friday to order the UK to reduce its diplomatic staff in Russia to equate the Russian presence in the UK.
Both countries have already expelled 23 staff. Moscow also ordered the closure of the British Council.
Sergei Skripal and his daughter Yulia collapsed in Salisbury, in England, on 4 March. Skripal remains in a critical but stable condition. Yulia's condition is said to be improving.