Russia hit back in its escalating diplomatic row with London on Thursday, expelling four British diplomats, retaliating against a similar measure announced by the Foreign Office earlier this week.

The four diplomats have 10 days to leave Russia, with Moscow reviewing future visa applications of UK officials, foreign ministry spokesman Mikhail Kamynin was quoted as saying.

On top of that, future cooperation on counter-terrorism would not be possible, he added.

London said on Monday it would expel four unnamed Russian diplomats, thought to be intelligence officers, after Moscow refused to hand over the main suspect in the investigation into the murder of Kremlin defector Alexander Litvinenko.

Litvinenko received political asylum in the UK in 2000 after falling out with newly-elected president Vladimir Putin.

He was poisoned last year using highly radioactive isotope polonium 210, with British investigators accusing Andrei Lugovoi, a former intelligence officer, of carrying out the plot.

London's decision to expel the diplomats has rankled with Russian politicians, with outspoken nationalist Vladimir Zhirinovski suggesting Moscow expels 12 diplomats, instead of four, and accusing Britain of systematically pursuing anti-Russian policies.

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