A number of unidentified drones have been spotted above three air bases in Britain.

The incidents saw “small unmanned aerial systems” spotted over RAF Lakenheath and RAF Mildenhall, in Suffolk, and RAF Feltwell, in Norfolk.

The United States Air Force (USAF), which uses these bases, said the sightings were recorded between November 20 and 22 and it was unclear at this stage whether the drones were considered hostile.

He also declined to say whether defense mechanisms had been used, but said he retained “the right to protect” the facilities.

A US Air Forces Europe spokesperson said: “We can confirm that small unmanned aerial systems (UAS) have been spotted near and above RAF Lakenheath, RAF Mildenhall and RAF Feltwell between November 20 and 22. The number of UAS has fluctuated. and they varied in size/configuration.

“The UAS were actively monitored and installation officials determined that none of the incursions impacted base residents or critical infrastructure.

“To protect operational security, we do not discuss specific force protection measures but we reserve the right to protect the installation. We continue to monitor our airspace and work with host nation authorities and mission partners to ensure the safety of base personnel, facilities and assets.

A UK Ministry of Defense spokesperson said: “We take the threats seriously and maintain robust measures at defense sites. This includes security capabilities against drones.

“We will not comment further on security procedures.”

Concerns have been raised this week over the country’s security due to Vladimir Putin’s latest televised speech. On Thursday, the Russian president said Moscow could strike the military facilities of any country whose weapons are used against Russia.

This sparked concerns in Washington and London, after US President Joe Biden authorized kyiv to use ATACMS on targets inside Russian territory and following reports of Storm missile launches British-made Shadow in Kursk.

During his speech, Putin confirmed that Russia had launched a medium-range hypersonic ballistic missile attack against a Ukrainian facility.