A fire has occurred on a bridge linking mainland Russia with the Crimean peninsula, according to Russian state-backed media.

RIA-Novosti and the Tass news agency quoted local Russian official Oleg Kryuchkov as saying an object thought to be a fuel storage tank caught fire and that traffic has been stopped on the bridge.

Images shared on social media purported to show fire and damage to the span.

The authenticity of the reports and images could not be immediately verified.

Russia Ukraine War
Smoke rises after big explosions in Kharkiv (Francisco Seco/AP)

The crossing is a pair of road and rail bridges that Russia built after it seized and annexed Crimea from Ukraine in violation of international law in 2014.

The 12-mile bridge across the Kerch Strait links Russia’s Taman peninsula with Crimea.

Russia opened the first part of the span to car traffic in May 2018. The parallel bridge for rail traffic opened the following year.

The bridge was Russia’s only land link to the peninsula until Russian forces seized more Ukrainian territory on the northern end of the Sea of Azov in heavy fighting, particularly around the city of Mariupol, earlier this year.

The fire occurred hours after explosions rocked the eastern Ukrainian city of Kharkiv early on Saturday, sending plumes of smoke into the sky and triggering a series of secondary explosions.

Kharkiv mayor Ihor Terekhov said the early-morning explosions were the result of missile strikes in the centre of the city.

He added that the blasts sparked fires at one of the city’s medical institutions and a non-residential building. There were no immediate reports of casualties.

The explosions came hours after Russia concentrated attacks in its increasingly troubled invasion of Ukraine on areas it illegally annexed, while the death toll from earlier missile strikes on apartment buildings in the southern city of Zaporizhzhia rose to 14.

On Friday, the Norwegian Nobel Committee awarded the Nobel Peace Prize to human rights organisations in Russia and Ukraine, and to an activist jailed in Belarus, an ally of Moscow.

Berit Reiss-Andersen, the committee’s chairwoman, said the honour went to “three outstanding champions of human rights, democracy and peaceful co-existence”, though it was widely seen as a rebuke to Vladimir Putin and his conduct of Europe’s worst armed conflict since the Second World War.

The president this week illegally claimed four regions of Ukraine as Russian territory, including the Zaporizhzhia region which is home to Europe’s largest nuclear power plant, whose reactors were shut down last month.

That move was foreshadowed by Russia’s annexation of Crimea in March 2014, which was carried out after Moscow alleged residents of the peninsula had voted to join Russia.

It was widely condemned, and prompted sanctions from the US and the EU.