Flights between the UK and Ukraine have been suspended as the crisis in the eastern European country intensifies.

Ukraine closed its airspace in the early hours of Thursday morning after Russia launched a major military assault.

The UK Foreign Office updated its travel advice to warn that British nationals in Ukraine “should not expect increased consular support or help with evacuating”.

Wizz Air cancelled its flights between Luton Airport and the Ukrainian cities of Kyiv and Lviv on Thursday.

Ryanair and Ukraine International Airlines (UIA) – the other carriers which fly between the UK and Ukraine – also suspended those routes.

Images from aviation website Flightradar24 show there are no civilian aircraft in Ukrainian airspace and very few over neighbouring Belarus, where many Russian troops are positioned.

Transport Secretary Grant Shapps banned aircraft flying to or from UK airports from using Ukraine airspace.

The Cabinet minister tweeted that he made the decision “following the horrific events overnight”.

He added: “I’ve instructed @UK_CAA (the Civil Aviation Authority) to ensure airlines avoid Ukraine airspace to keep passengers and crew safe.

“We continue to stand with the people of Ukraine and work with our international partners to respond to this act of aggression.”

Ryanair said it has suspended its flights to and from Ukraine for “at least the next 14 days” and has removed them from sale for “at least the next four weeks until further information becomes available from EU safety agencies”.

It added: “Ryanair remains committed to our services to/from Ukraine and we look forward to restoring flight services there as soon as it is safe to do so.

“We sincerely regret and apologise for these unprecedented disruptions and any inconvenience that they will inevitably cause to our Ukrainian customers.”

A Wizz Air spokeswoman commented: “The safety and security of our passengers and crew remains our number one priority and we hope normality will return to Ukraine soon.”

UIA said it “takes all possible measures to ensure the safety of our passengers”.

The lack of flights will make it harder for British nationals to evacuate from Ukraine to the UK.

The Foreign Office updated its travel advice to state: “Ukraine’s airspace is closed. It is likely that commercial routes out of Ukraine will be severely disrupted and roads across Ukraine could be closed.”

It added: “Russia’s military action in Ukraine will severely affect the British Government’s ability to provide consular assistance in Ukraine.

“British nationals should not expect increased consular support or help with evacuating in these circumstances.”

On Tuesday, Foreign Secretary Liz Truss urged Britons in the country to “leave now via commercial routes while they are still available”.

Flights are continuing to operate over Russia, which is a route used by many services between the UK and Asia.

In July 2014, Malaysian Airlines flight MH17 was shot down by a missile launched from an area of Ukraine controlled by pro-Russia separatists, killing all 298 people on board.