Russian diplomats leave UK amid spy row

London  :   The 23 Russian diplomats that UK's Prime Minister Theresa May expelled following the alleged poisoning of an ex-spy were on Tuesday making their way out of the country.

Last week, May expelled the diplomats after saying Russia was "culpable" for the poisoning of Sergei Skripal and his daughter, who remain in critical condition after being targeted by what was believed to be a nerve agent produced in Russia.

The diplomats and their families were seen saying goodbye to colleagues and friends outside the Russian Embassy in London, the BBC reported.

Later in the day, the government will decide whether to impose further sanctions on Russia. May was chairing a meeting of the National Security Council.

Moscow denied involvement in the attack and announced expelling 23 British diplomats in response. The UK diplomats have until Saturday to leave Russia.

The Kremlin is also closing down both the British Council in Russia, which promotes cultural ties between the nations, and the consulate in St. Petersburg.

The Russian Embassy said around 80 people -- including the Russian diplomats and their families -- were leaving London on Tuesday, which is the deadline given by May.

More than two weeks on from the attack, the head of counter-terrorism policing in the UK, Met Police Assistant Commissioner Neil Basu, said the focus of the Salisbury investigation is "on the movements of the Skripals".

British Foreign Secretary Boris Johnson said on Monday that technicians from the Organization for the Prohibition of Chemical Weapons were collecting samples in order to launch an investigation.

Skripal and his daughter were found slumped over a bench in the southern English town of Salisbury on March 4 by a police officer who also had to be hospitalized.

Meanwhile, following a phone call between Japanese Prime Minister Shinzo Abe and May, Downing Street said Japan condemned the Salisbury attack and "shared our outrage".

The leaders of France, Germany and the US have already pledged support for the UK in a joint statement and the EU offered its "unqualified solidarity".