A major factory in Russia reported to be involved in rebuilding a Crimean bridge went up in flames in the early hours of Saturday following a suspected stealth Ukrainian missile strike across the border.

Local media reported that the plant, in the Borisovsky district of the Belgorod region, produces spare parts for bridges and was expected to help reconstruct the Kerch Strait Bridge, which was severely damaged in a Ukrainian attack last year.

Videos posted by local residents on social media showed a blaze rising over the plant on the horizon that was visible from a few kilometres away and lit up the pre-dawn sky.

Vyacheslav Gladkov, the governor of the Belgorod region, said in a statement that the fire caused by a Ukrainian strike had been contained and that firefighters were “doing their best to minimise the damage”.

He added that the attack did not cause any casualties and did not name the target of the attack.

Mr Gladkov said he would ask Vladimir Putin to raise the terrorist threat level in the region to an indefinite yellow owing to the recent attack.

Belgorod, which is 124 miles north of Kharkiv, had been on a temporary yellow threat level since Ukrainian attacks on the border city began last year, and authorities have been rolling it over ever since.

“The need for extending the yellow terrorist threat leave is absolutely clear. We will lift the restrictions as soon as the situation improves,” Mr Gladkov said.“Safety of Belgorod residents is the most important thing right now.”The yellow threat level means a tangible risk of an attack, which requires citizens to avoid public places and gives authorities broader powers.

Saturday’s fire at the plant is a major embarrassment for the Kremlin as earlier this week, the Russian president publicly urged the Russian military to “eliminate the very possibility of attacks” on the border areas such as Belgorod.

Putin also instructed the government to allocate extra funds to deal with the aftermath of Ukrainian spill-over attacks.

Stray shells have been landing in villages on the Russian side of the border since the start of the invasion of Ukraine last year, causing damage and occasionally injuring people.

At least 36 people in Russian border areas have been killed and 132 injured since the start of the war, according to the latest tally by Novaya Gazeta Europe, the Russian media outlet. Most of the victims hailed from the Belgorod region