Russia threatens Britain with attack after UK okays Ukraine strikes within Russia

• Russia says it may attack British military installations as the UK is now part of the Ukraine conflict.
• UK foreign secretary David Cameron last week said Ukraine can use British weapons to strike targets within Russia.
• Britain should consider the "catastrophic consequences", Russia says, including attacks on any British facilities " on the territory of Ukraine and abroad".

Russia warned Britain on Monday that if British weapons were used by Ukraine to strike Russian territory then Moscow could hit back at British military installations and equipment both inside Ukraine and elsewhere.

British Ambassador Nigel Casey was called to the foreign ministry for a formal protest after Foreign Secretary David Cameron said last week that Ukraine had the right to use British weapons to strike Russia.

Britain denied that Casey had been summoned, saying that he had met Russian officials "for a diplomatic meeting" in which he "reiterated the UK's support for Ukraine in the face of unprovoked Russian aggression".

Russia's foreign ministry said the Cameron remarks recognised that Britain was now de facto a part of the conflict and contradicted an earlier assurance that long-range weapons given to Ukraine would not be used against Russia.

READ | Cold War 2.0? Russia to launch tactical nuclear drills because of 'provocative statements'

"Casey was warned that in response to Ukrainian attacks on Russian territory with British weapons, any British military facilities and equipment on the territory of Ukraine and abroad" could be targeted, the Russian foreign ministry said.

The ministry said it considered Cameron's remarks a serious escalation.

"The Ambassador was called upon to reflect on the inevitable catastrophic consequences of such hostile steps by London and immediately refute the belligerent provocative statements of the head of the Foreign Office in the most decisive and unambiguous way."

Cameron, during a visit to Kyiv last week, told Reuters that Ukraine had a right to use the weapons provided by Britain to strike targets inside Russia, and that it was up to Kyiv whether or not to do so.

The British foreign office spokesperson said on Monday Casey had also restated "the UK's position on providing support to Ukraine" in the meeting with Russian officials.