Russia is planning to demand an official explanation from the UK as to why an Aeroflot passenger plane was subjected to a search at London’s Heathrow Airport (LHR) on March 30, 2018, warning it would reserve the right to conduct similar actions against British airlines if a response is not received.

Russia claims that UK customs authorities, without explanation, boarded and searched the Aeroflot passenger plane originating from Moscow once it landed at Heathrow Airport on March 30, 2018, and passengers disembarked, Radio Free Europe reports. 

In a press release, on March 30, 2018, the Russian Embassy in London stated: “(British) Border Force and Customs officers have searched the aircraft that was conducting the Aeroflot flights 2582 / 2583, Moscow – London – Moscow.... After the search was over, the British officers refused to provide any written document that would specify the reasons for their actions, their legal foundation and their outcome.”

The Embassy claims that British officials tried to search the aircraft without the crew being present, and that only after negotiations involving an Embassy officer, the captain of the aircraft was allowed to take part in the search. The Embassy says it sent a diplomatic note demanding that the UK provides an explanation for the incident.

On March 31, 2018, the Russian Ministry of Transport also demanded for an official explanation from the British authorities, warning that if London does not clarify the incident, Russia would consider the search illegal and subject UK airlines to similar actions: “If there is no explanation, the Russian side will deem the actions towards our plane as illegal and also reserve the right to take similar action against British airlines,” it said in a statement, according to Reuters.

Meanwhile, British Security Minister Ben Wallace stated on March 31, 2018, that it was "routine for Border Force to search aircraft to protect the U.K. from organized crime and from those who attempt to bring harmful substances like drugs or firearms into the country," Radio Free Europe reports.

The incident comes amid severe strains between the two countries.