He'd hardly know a Beretta from a Bazooka, but Anton Zaika can sure find his way around a blacksmith's forge -- and he is helping Ukraine's war effort in his own unique way.

The talented artisan had carved out a modest but successful business selling metal furniture to wealthy European clients, but war came five months ago and changed his priorities.

Now he makes anti-tank barriers to protect the local volunteer battalion in the northwestern frontline city of Sumy, and special iron stoves adapted to trenches to keep them warm.

His services come free-of-charge to the local territorial defence unit fighting the Russian invasion, and he has even started buying and converting beat-up old cars into makeshift armoured personnel carriers.

"After the first day of the war, there were no police anymore in the city and not much army," Zaika, 32, told AFP at his workshop in Sumy, a city of 260,000 people just 25 kilometres (16 miles) from Ukraine's border with Russia.

"So, we've mainly had a territorial defence. It was our citizens who took up arms and stopped the enemy from entering the city. I'm no good at weapons, so I did what I was good at to help them."

When Russia invaded Ukraine, Anton Zaika switched from making furniture to anti-tank barriers
When Russia invaded Ukraine, Anton Zaika switched from making furniture to anti-tank barriers AFP / Genya SAVILOV

Sumy, which can trace its history back to its founding by the Cossacks in the mid-17th century, found itself battling for survival from the start of Moscow's assault on Ukraine in February.

Almost captured by the Russians, the city quickly fought back over six intense weeks of fierce street-to-street urban warfare as part of a wider Ukrainian counteroffensive.

But it remained surrounded and bombarded daily by artillery -- with trains and buses out of the city suspended, roads and bridges pulverised, and its population trapped, their food and water running dangerously low.

Air strikes continued into summer, as Russian ground forces made repeated attempts to retake the city.

The public have been chipping in, bringing materials they found that could be put to use in the trenches or in military shelters
The public have been chipping in, bringing materials they found that could be put to use in the trenches or in military shelters AFP / Genya SAVILOV

Zaika, who has run the business for seven years since learning the metalwork trade from his father, had hoped to build another workshop with around 25,000 euros of metal he had bought.

But he used up the entire stockpile within the first month of the war as he began getting requests for help from the local territorial defence unit.

He has since made more than 500 stoves for fighters but also to make life more liveable for people in bomb shelters and in nearby towns and villages where the gas supply had been knocked out by shelling.

Eventually the public began to chip in, bringing materials they had found that could be put to use in the trenches or in military shelters.

Zaika says he remembers one patriotic donor walking six kilometres in snow with a stack of electrodes weighing around 20 kilograms (45 pounds).

Others contributed through a fundraising page on Instagram, giving Zaika enough cash to pay for an early 2000s Suzuki XL 7 people carrier that he gave a military makeover and handed to the volunteer forces.

"We added frame protection and engine protection, we strengthened the front bumper, radiator and trunk and gave the windows metal grills," he told AFP.

"With the pickups, we also fit a metal frame that you can attach an awning to and a rack for a machine gun."

Zaika, who has a six-year-old son and a 16-week-old daughter, has converted 10 cars so far -- adding Dodges, Fords and Mitsubishis to the Suzuki and sending each one off to the front.

"I'm not planning on stopping. Winter is coming soon so I'm sure we will need to make more stoves," he told AFP.

"And with the cars, if the guys come back asking for more help, we're here to help them."