Ukraine’s military launched an attack on Russia’s bridge over the Kerch Strait last month, Kyiv has confirmed.

The attack on the strategically important route linking Russia with Crimea led Moscow to restrict passage of ships through and flights over the Strait.

The incident on 17 July marks the second time the structure was hit.

Russia said marine-based drones were used in the attack, which left two people dead.

Kyiv officials claimed responsibility for damaging the bridge on Thursday, following a period of ambiguity.

The bridge is a vital re-supply route for Russian forces occupying parts of southern Ukraine. It is one of the key ways Moscow reinforces its troops in the Crimean peninsula – a Ukrainian territory annexed by Russia in 2014 – and the southern Kherson region.

In July, Moscow blamed Ukraine for what it called a “senseless” and “cruel” attack and vowed to retaliate.

But on Thursday one of Ukraine’s most senior security officials appeared to mock the idea that the Russians had the bridge under heavy protection.

Describing the bridge as one of many Russian facilities deemed to be “untouchable”, Oleksiy Danilov said Ukraine was putting that claim “where it belonged”.

Ukraine had shown that it was more than capable of penetrating Russia’s defences, Mr Danilov said.

His words came as Kyiv sought to accelerate its counter-offensive which aims to retake territory in southern and eastern Ukraine. Any attack that forces Russia to limit traffic coming via the bridge will further complicate Moscow’s logistical challenges.

July’s attack is the second major incident on Russia’s bridge over the Kerch Strait in the past year. It was partially closed following a huge explosion last October, and then fully reopened in February.