The United Kingdom government says a UK citizen has been killed in Ukraine and another is missing.
The Foreign Office confirmed on Thursday that it is supporting the family of a UK man killed in Ukraine.
It also said it was "urgently seeking further information" on another Briton who is missing.
The government did not provide further details.
Sky News reported that the two were believed to have been fighting with Ukrainian forces against the Russian invasion.
Volunteers from the UK and many other countries have travelled to Ukraine to fight despite being discouraged from doing so by their governments.