Russian Orthodox priests have visited the scene of a huge fire at a fuel depot, which continues to burn three days after being set alight in a Ukrainian drone attack.

More than 500 firefighters have been tackling the giant blaze at the Proletarsk oil storage facility in the southern Rostov region.

About 20 of 74 storage tanks were on fire, local authorities told the RIA news agency.

On Wednesday, local Orthodox priests said prayers next to the fire engines and brought an icon to the scene in support of firefighters’ efforts.

“The [priests] spoke with the firefighters and blessed all the fire equipment,” the local Volgodonsk eparchy – the Russian Orthodox Church equivalent of a diocese – told Reuters news agency.

They brought with them a large icon of the Unburnt Bush, considered a talisman against fire.

According to regional governor Vasily Golubev, air defences shot down the Ukrainian drone on 18 August, but its debris caused diesel fuel to ignite on the territory of the facility.

The authorities have declared a state of emergency, but the local city administration, quoted by Russian state media, said there was no threat of the fire spreading to residential areas and called on people “not to give in to panic”.

Mr Golubev said 41 firefighters had received medical treatment for the effects of the blaze, including five who had been placed in emergency care.

Ukraine has not commented on the strike – but its forces have been targeting Russia’s oil infrastructure as part of their efforts to counter Moscow’s full-scale invasion, which began in February 2022.

Also on Wednesday, Ukrainian forces reported striking an S-300 air defence system near the Russian city of Novoshakhtinsk in Rostov region.

The strike was carried out by the Ukrainian Navy in co-operation with other units, the general staff of the Ukrainian armed forces said on Facebook.

“Ukraine’s defence forces continue to weaken Russian invaders’ air defence,” it said.

“It is worth noting that Russian invaders also use S-300 systems for strikes on peaceful Ukrainian cities, destroying residential buildings and terrorising civilian population,” it added.

Elsewhere on Russian soil, Moscow said its air defences had shot down 11 Ukrainian drones targeting the city overnight.

The city’s mayor, Sergei Sobyanin, said it was one of the biggest attacks on the Russian capital since the conflict started, but there were no reports of damage or casualties.

At the same time, Ukrainian defences reported stopping 50 Russian drones and missiles.

“The enemy continues to attack our region with strike drones. The air raid lasted all night and into the morning for more than nine hours,” Kyiv’s military administration said on Telegram.

A private house was damaged by falling debris, while power lines were severed, it added.

On the ground, Ukraine is continuing to hold a swathe of territory in Russia’s western Kursk region, following its cross-border incursion that began on 6 August.

It is the first time that Russian territory has been occupied by a foreign power since World War Two.

In his video address late on Wednesday, Ukrainian President Volodymyr Zelensky said “our combat work continues” in the Kursk region.

“We control the designated areas,” he said without providing any details.

In Russia’s adjacent Bryansk region, Governor Aleksandr Bogomaz said an incursion attempt by a Ukrainian reconnaissance group was repelled on Wednesday.

This comes as Russian forces are continuing to press hard towards the city of Pokrovsk in Ukraine’s eastern Donetsk region.

Ukraine’s officials said earlier this week the Russians were now about 10km (six miles) from the outskirts of Pokrovsk, a key logistics hub in the area.