The family of a British man missing in Ukraine say they are "very worried" about his health and whereabouts.
Chris Parry, 28, was last seen on Friday with Andrew Bagshaw, 48, heading to the town of Soledar, which has seen intense fighting in recent days.
The two men had been working as volunteers helping people evacuate from the frontline of the war.
Mr Parry's family and partner say he is an extraordinary person who is "compassionate and caring".
They added he "would not be dissuaded from his work in Ukraine liberating elderly and disabled people, which we are very proud of" and that they "all love him very much".
Mr Parry, originally from Truro in Cornwall but living in Cheltenham, had travelled to Ukraine last year to do humanitarian work after the Russian invasion.
He said he had a "drive to help" during an interview with BBC Cornwall from Ukraine over Christmas last year.
He also described the "continuous" bombardment, as well as recalling the time he had a drone "within about 10 metres of my face" while he was on the front line.
A missing person's report was filed for the two men from the police department in the city of Bakhmut in the Donetsk region at 17:15 local time on Saturday.
Ukrainian police said the men had been in Kramatorsk - where there have been reports of strikes in recent days - but were last seen heading to the small, eastern town of Soledar.
The UK's Ministry of Defence said on Tuesday that Russia was "likely" in control of most of Soledar following a months-long battle with Ukrainian forces.
Gaining control of Soledar would be Russia's biggest gain since last August if it is confirmed.
The capture would be significant as it would allow Russia to gain access to Soledar's deep, city-like network of salt mine tunnels, which have been dormant since April.
It would also allow Russian troops to get closer to the nearby larger city of Bakhmut, where Russian forces have been fighting for months to capture.
The family of Mr Bagshaw, who is also missing, described their son as "a very intelligent, independently minded person, who went there as a volunteer to assist the people of Ukraine".
In a statement issued to the media in New Zealand - where Mr Bagshaw lives - his parents described the work he has been doing as delivering food and medicines and helping elderly people move from "near the battlefront of the war".
The British Foreign Office is warning against all travel to Ukraine due to attacks on a number of different cities currently taking place, as the conflict continues into its 11th month.
It says there is a "real risk to life", adding that British nationals still in Ukraine should leave immediately.
