Blackened by smoke and dripping with sweat, firefighters in Ukraine's second city Kharkiv are totally exhausted after two months of chasing blazes sparked by the constant explosion of Russian rockets.

Since Russia invaded on February 24, there have been more than 1,000 fires in the eastern Kharkiv region which borders Russia, the area's emergency services spokesman Yevgen Vasylenko said.

In the city alone, over 2,000 buildings have been damaged or destroyed by fire and more than 140 civilians have died beneath the wreckage, he said.

Every day, Russian rockets are fired at Kharkiv, most of which target districts in the east or northeast that lie closest to the frontier and where civilians still live. Sometimes deadly, they strike at random both in daylight and at night.

In the eastern city of Kharkiv, over 2,000 buildings have been damaged or destroyed by fire and more than 140 civilians have died beneath the wreckage
In the eastern city of Kharkiv, over 2,000 buildings have been damaged or destroyed by fire and more than 140 civilians have died beneath the wreckage AFP / Dimitar DILKOFF

Two strikes late on Wednesday killed one person and wounded two others. And on Tuesday, three people died.

"Usually its only one major fire or two at a time to extinguish but during the war, you can have like 12 or 15 major fires at the same time," explains Roman Kachanov, a fireman and judo expert who heads the N11 fire station.

"Two weeks ago there was a big shelling in the city centre and 56 fire trucks went in to extinguish different areas... a lot of apartments were bombed. And then they started to bomb Saltivka," he said, speaking in English, referring to a badly-hit area in the northeast.

"And this has been going on day after day and people don't have enough time to rest," he told AFP.

"It's exhausting, you're just as tired as hell."

Over the past two months, one firefighter and three bomb disposal experts have died in the Kharkiv region
Over the past two months, one firefighter and three bomb disposal experts have died in the Kharkiv region AFP / Dimitar DILKOFF

On Wednesday after tackling a blaze at a garage, one firefighter with a blackened face, his body drenched in sweat, just sat for a long while, his features drawn, his gaze empty.

This week, they were visited by a small group of American firefighters who came to deliver equipment and give them first-aid training.

Behind the barracks, where a handful of ancient fire engines dating back to the Soviet era are parked alongside newer vehicles, Kachanov shows his visitors an impressive collection of rocket shrapnel, in a striking image of the multiple attacks staged against the city.

Asked about the risks given that the Russians often target the same place twice, firing 10 or 15 minutes after the initial strike, he brushes it off as just part of the job.

"When there's a shelling you have to go there but for now if there's a new bombing (while we're working), we probably won't even notice it," he says wearily.

Since Russia invaded Ukraine on February 24, there have been more than 1,000 fires in the eastern Kharkiv region which borders Russia
Since Russia invaded Ukraine on February 24, there have been more than 1,000 fires in the eastern Kharkiv region which borders Russia AFP / Dimitar DILKOFF

"To us, work is just work."

Over the past two months, one firefighter and three bomb disposal experts have died in the Kharkiv region on the job, the emergency services said.

"One of my firefighters died in shelling right in front of me while extinguishing a fire at a market," says Kachanov, without explaining further.

As well as their firefighting gear, which is protective if uncomfortable, weighing some 10 kilogrammes (22 pounds), some firefighters also wear bullet-proof vests.

"Right now we have 3,000 firefighters in the Kharkiv region working together as a team. We have all five stations working so we have enough people," he says.

And there has been no shortage of volunteers coming forward to help out.

Ex-Marine Clint Saint-Martin is one of the American firefighters who have come over to show solidarity with their Ukrainian colleagues.

After visiting the fire station closest to the northeastern area of the city, he smiles as he poses for a photo in his US firefighters' helmet.

"This is the first team of hopefully many coming to Ukraine to support Ukrainian firefighters in their mission against this insane war," he told AFP.

"I served in Iraq but.. we've had a few (rockets) land around us today and they don't even bat an eye. It's really impressive. I've got a lot of respect for these guys," he said.

"Hopefully we'll send since several more teams but I'd come back in a heartbeat. These people just inspire me."

"We hope the Russians will understand who this 'Putler' is and maybe they'll kick his ass out of the Kremlin," he said, using an offensive term fusing Russian President Vladimir Putin's name with that of Adolf Hitler.