With gunfire crackling in the distance, soldiers on Ukraine's eastern frontline say there has been little let-up in fighting since Russia pulled back its troops from their country's borders.

"Unfortunately we're still feeling this escalation," said Stanislav Shukh, a 35-year-old Ukrainian soldier in Shyrokyne in southern Ukraine.

War-scarred facades line abandoned streets in the former resort town, which is a key position for Ukrainian soldiers in their conflict with pro-Russia separatists.

Ukrainian soldiers say little let-up in fighting along borders with Russia
Ukrainian soldiers say little let-up in fighting along borders with Russia AFP / Aleksey Filippov

A recent uptick in fighting between the two sides saw Russia mass tens of thousands of troops on Ukraine's borders and leaders in Moscow, Washington, and European capitals trade accusations of fuelling the escalation.

The separatists are widely seen as having Russia's political and military backing, which Moscow denies.

The Kremlin said last week it had withdrawn troops but Ukrainian soldiers dug in at Shyrokyne say they are on alert and the atmosphere is still tense.

The latest fighting along Ukraine's border with Russia has shredded hopes of a lasting ceasefire
The latest fighting along Ukraine's border with Russia has shredded hopes of a lasting ceasefire AFP / Aleksey Filippov

"Some Russian troops did leave territory near our border, but all their equipment -- which can be very easily moved for an escalation -- remained," Shukh added.

Shyrokyne on the Azov Sea was abandoned by residents and nearly completely destroyed in fighting that broke out in 2014 after Moscow annexed the Crimean peninsula, spurring harsh condemnations and sanctions from the West.

The conflict has claimed more than 13,000 lives and the fresh fighting that intensified at the beginning of the year shredded hopes that a ceasefire brokered in July might wind down the fighting completely.

Some 30 Ukrainian soldiers have been killed since the start of the year compared to 50 in all of 2020, while the separatists have reported at least 20 military deaths since January.

Ukraine's President Volodymyr Zelensky has urged soldiers along  Crimea border to remain on alert
Ukraine's President Volodymyr Zelensky has urged soldiers along Crimea border to remain on alert AFP / Aleksey Filippov

On Tuesday, another Ukrainian soldier was killed and three more injured when their vehicle hit an explosive device, officials in Kiev said.

Gotcha, a Ukrainian soldier of Georgian origin, rests in a dugout in the village of Shyrokyne
Gotcha, a Ukrainian soldier of Georgian origin, rests in a dugout in the village of Shyrokyne AFP / Aleksey Filippov

During a visit to the border with Crimea on Tuesday, President Volodymyr Zelensky warned soldiers stationed there to stay on the alert.

"The fact the troops are withdrawing doesn't mean the army should not be ready for the possibility troops could return to our borders any moment," he said wearing military green.

Echoing assessments from military officials in the capital Kiev, some 650 kilometres (400 miles) southwest of Shyrokyne, Ukrainian soldiers said the fighting was continuing unabated.

"The enemy's activity has been consistent recently," Shukh told AFP, saying they had been targeted by separatists with "all types of weapons".

"You can see there is shelling here," said Gocha, a Ukrainian soldier who declined to give his last name, as Kalashnikovs and mortars fired in the background.

It's a pattern of ceasefire violations that war monitors say is being repeated across the frontline.

The Organization for Security and Co-operation in Europe (OSCE) in its last report Monday said there were 390 violations between Friday evening and Sunday evening in the breakaway Donetsk and Lugansk regions compared to 332 during the previous weekend.

"Nothing changed in the east," a Ukrainian military official told AFP on the condition of anonymity.

Pentagon press secretary John Kirby said this week that Washington had registered movements of some Russian troops away from Ukraine's borders but said it was "too soon to tell" whether Russia was pulling back all forces.

"We're going to keep watching this very, very closely," Kirby told journalists during a briefing at the Pentagon.

"It's just a trick," said Ukrainian soldier Gocha.

"They are showing the whole world that they are leaving, but so far I only hear bang-bang, like a brass band".

Oleksandr Lytvynenko, head of the National Institute for Strategic Studies, told AFP that worries in Kiev over a return of Russian troops to the border could become routine and a "regular part of Ukraine's political calendar".

"It's going to be like this from now on," he explained.