Russian air force chiefs sparked an attack scare by planting war plane transponders on military vehicles, it was claimed tonight.
The ruse looked like 30 military planes grouping up and moving in circles at west Russian airports close to the Ukraine border.
If it was a “spoof manoeuvre” security experts suspect it was to hide another “activity” happening elsewhere and keep NATO guessing.
British Rivet Joint spy planes are known to have been flying patrols over Ukraine to hoover up Russian radio chatter and other communications.
They are there to provide an early warning of where and when an attack might be launched by Russian forces moving into Ukraine.
Alarmingly Moscow’s air force planes have been steadily increasing in number in airports to the west of Russia without being involved in exercises.
Around 126,000 Russian combat troops are gathered close to the Ukraine border, along with 30,000 pro-Moscow separatists in contested Donbas.
Russia also has a large number of regular and special forces bolstering Donbas separatists, although Moscow has repeatedly denied this.
An expert in Russian military matters told the Daily Mirror: “I haven't seen anything like this before. Air force people in the UK are baffled.
“Circuiting round and round and up and down a large airfield is not a recognised manoeuvre.
“These aircraft could be seen moving all day, burning fuel.
“So it was likely a spoof with jeeps or cars meandering around with transponders on them.
“This could mean not that nothing is happening, but something is happening elsewhere that we cannot detect."
Russia has warned it would quickly take "retaliatory measures" if the US and its allies reject its security demands regarding NATO membership.
Russia has demanded guarantees that Nato will never admit Ukraine and other ex-Soviet nations as members and that the alliance will roll back troop deployments in ex-Soviet bloc countries.
Russian foreign minister Sergei Lavrov said he and other top officials would advise President Vladimir Putin on the next steps after receiving written replies from the US to the demands.
He said: "If the West continues its aggressive course, Moscow will take the necessary retaliatory measures."
Nato is bolstering its deterrence in the Baltic Sea region and the US ordered 8,500 troops on higher alert for potential deployment to Europe.
Western nations including the UK have also sent plane loads of weapons to help Ukraine strengthen its defences.
