LONDON, March 31 (Xinhua) -- A British official said on Saturday it was routine for border officials to search aircraft, after Russia demanded an official explanation over the alleged searching of an Aeroflot passenger plane by British officials at London's Heathrow airport on Friday.
British Security Minister Ben Wallace said in a statement that it was "routine for Border Force to search aircraft to protect the UK from organized crime and from those who attempt to bring harmful substances like drugs or firearms into the country".
"Once these checks were carried out the plane was allowed to carry on with its onward journey," he added.
The Russian Embassy in the Britain in a statement released Friday called it a "blatant provocation" by the British authorities.
The passenger jet was searched upon landing at Heathrow Airport following a scheduled flight from Moscow on Friday, according to the Russian embassy, saying that this kind of event is "extraordinary."
The Russian embassy said the British officials tried to search the aircraft without the crew being present, which is "something categorically prohibited by the rules in force."
"After an Embassy officer arrived at the airport long negotiations were conducted that allowed to ensure the right of the captain to be take part in the search. 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 said in the statement, suggesting that the plane had been searched in connection with the diplomatic crisis which has erupted following the Salisbury spy poisoning.
The Russian embassy said the attempts to get in touch with the Britain's Foreign Office in order to clarify the reasons of the inappropriate behavior of British officials did not bring fruit, and it has sent a diplomatic note demanding the British side to provide explanations of the incident.
On Saturday, Russia's Transport Ministry also said it wanted to know what had happened. "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.
SPY ROW
Relations between Russia and the West have been strained after former Russian double agent Sergei Skripal and his daughter Yulia were found unconscious on a bench outside a shopping center in Britain's Salisbury on March 4.
British Prime Minister Theresa May said the substance used in their poisoning was a Novichok-class nerve agent developed in former Soviet Union. London expelled 23 Russian diplomats and announced a series of restrictive measures against relations with Russia. More than two dozen countries also announced the expulsion of around 150 Russian diplomats, in a sign of showing support to Britain.
Moscow denies involvement in the incident. Russian Foreign Ministry on Friday asked Britain to downsize its diplomats stationed in Russia to the same level as Russia has in Britain within a month in retaliation to measures imposed following the Salisbury incident. The ministry informed ambassadors of 23 countries of its decision to expel employees of their diplomatic missions in Russia in a tit-for-tat response to the recent hostile actions by their countries against Moscow.