Three buses believed to be carrying expelled American diplomats have departed from the U.S. Embassy in Moscow.

Before the Thursday morning departure, journalists outside the embassy compound saw people leaving the residences, placing luggage on trucks. Some carried pet-carriers.  

Their departure is the result of a row over the nerve agent attack on a former Russian spy and his daughter in the UK.

Sergei Skripal and his daughter Yulia were found unconscious on a bench in the city of Salisbury last month. Britain alleges Russian involvement, which Moscow vehemently denies.

Russia has meanwhile called for urgent UN Security Council talks on the spiraling diplomatic crisis sparked by the spy poisoning scandal.  

On Wednesday it convened a meeting of the Organisation for the Prohibition of Chemical Weapons (OPCW) but was unable to get the required two-thirds of votes from members to approve a joint investigation into the incident.

Six countries voted in favour of the Russian draft motion but 15 were against while 17 abstained, mainly countries from the Non-Aligned Movement (NAM). 

Moscow last week ordered 60 American diplomats to leave the country by Thursday in retaliation for the United States expelling the same number of Russians.

More than 150 diplomats have been expelled by Britain and its allies, and Russia has ordered reciprocal moves.

Read more on dailymail.co.uk.