British nationals Chris Parry and Andrew Bagshaw, who were reported missing in eastern Ukraine, have been killed, their families have said.
Mr Bagshaw, 47, and Mr Parry, 28, were last seen heading to the city of Soledar on 6 January.
Mr Bagshaw’s family said the pair were attempting to rescue an elderly woman when their cars were hit by a shell.
The family of Mr Parry said the men had died while “attempting a humanitarian evacuation”.
Earlier this month, the Russian mercenary group Wagner claimed the body of one of the men had been found.
Soledar had been the focus of intense fighting and earlier this month Russia’s military claimed to have captured the Ukrainian salt-mine time town after a long battle.
In a statement issued by the UK Foreign Office, Rob, Christine and Katy Parry wrote: “It is with great sadness we have to announce that our beloved Chrissy has been killed along with his colleague Andrew Bagshaw whilst attempting a humanitarian evacuation from Soledar, eastern Ukraine.”
Speaking of Mr Parry, originally from Truro in Cornwall, they said: “His selfless determination in helping the old, young and disadvantaged there has made us and his larger family extremely proud. We never imagined we would be saying goodbye to Chris when he had such a full life ahead of him. He was a caring son, fantastic brother, a best friend to so many and a loving partner to Olga.
“Chris was a confident, outward looking and adventurous young man who was loyal to everyone he knew. He lived and worked away as a software engineer but Cornwall was always his home. He loved rock climbing, cycling, running and skydiving and wanted to travel the world.
“He found himself drawn to Ukraine in March in its darkest hour at the start of the Russian invasion and helped those most in need, saving over 400 lives plus many abandoned animals.
“It is impossible to put into words how much he will be missed but he will forever be in our hearts.
“We feel so privileged that he chose our family to be part of.”
Mr Parry and Mr Bagshaw had been in the Donetsk region of eastern Ukraine doing voluntary work.
Scientific researcher Mr Bagshaw was a British national but lived in New Zealand. He had been a volunteer in Ukraine since April.
His parents, Dame Sue and Prof Phil Bagshaw, said the men had been delivering food and medicines and helping the elderly.
In a statement released via news outlets they said Mr Parry and Mr Bagshaw “were attempting to rescue an elderly woman from Soledar, in an area of intense military action, when their car was hit by an artillery shell.
“Andrew selflessly took many personal risks and saved many lives; we love him and are very proud indeed of what he did.”
They added: “The world needs to be strong and stand with Ukraine, giving them the military support they need now, and help to rebuild their shattered country after the war.”
Cherilyn Mackrory, the Conservative MP for Truro and Falmouth, tweeted: “My deepest condolences to the family of my constituent Christopher Parry, whose death in Ukraine has been confirmed by the Foreign Office.
“My thoughts are with his family at this time, and I understand they are receiving support from Foreign Office staff.”
The Foreign Office has previously warned against all travel to Ukraine, saying there is “a real risk to life”.
British nationals still in Ukraine should leave immediately if it is safe to do so, it said.
Mr Parry previously spoke to the BBC Radio Cornwall on 2 January from the Bakhmut area in eastern Ukraine.
Explaining his motivation for being there, he wanted to help children particularly.
“To be able to get them out of these war-torn areas, it makes it definitely more worthwhile than anything else that I can imagine,” he said.
“Yesterday I had a drone within about 10 metres of my face which was one of my scariest times here… generic bombardment overhead you just haven’t got the time or effort to be able to flinch for everyone because you’d spend half you life sitting on the floor.”
On 3 January, three days before the volunteers disappeared, Mr Parry told a freelance journalist he had been volunteering as an evacuation driver.
He said: “I receive requests from family members who ask us to go and collect their relatives…
“A lot of volunteers won’t go anymore, but there are people there who want to get out, so I’m willing to go.”