Russian state controlled oil pipeline operator Transneft has reported an overnight drone attack at a transshipment facility’s oil storage tanks in the country’s southwest.

The facility in the Bryansk region serves the southern leg of the Druzhba oil export pipeline that carries Russian oil to Hungary, Slovakia and the Czech Republic.

Since the beginning of May, unidentified drones have hit several oil facilities in southern Russia’s Krasnodar region, and also a major storage depot next to the port of Sevastopol in Russia-annexed Crimea.

The Ukrainian section of the Druzhba pipeline has also suffered damage following repeated damage from Russian missle attacks since the start of the war between the two nations early last year.

Transneft told Russian state news agency Tass: “In the early morning [of Wednesday], an attempt of a terrorist act was undertaken against the Druzhba pipeline network at the Bryansk transshipment point. No one has been injured in the result.”

A Russian social network channel reported earlier on Wednesday morning that three storage tanks were hit at the transshipment facility near the village of Sven in Bryansk during two attacks by unidentified drones.

The closest border between Russia and Ukraine is about 100 kilometres away from the attacked facility.

Transneft has not released more details, but reports alleged that the tanks were empty at the time of the attack and had not ignited.

The company said the Druzhba pipeline network has been targeted by several unsuccessful drone attacks since Rusia’s invasion of Ukraine early last year, with the most recent incident occurring at the Novopskov pumping station in March.

A Transneft spokesperson told Tass that the Novopskov station had remained idle since the beginning of this year.

The Druzhba pipeline — also known as the Friendship pipeline — was built by the Soviet Union to carry oil from Western Siberia to Eastern Europe.

It has been operating well below nameplate capacity since December last year following the European embargo on imports of Russian oil.

The network has been reported as delivering some volumes to Hungary and Slovakia, which are exempt from the embargo because of their geographical position and lack of immediate access to alternative oil supplies.

Transit tariff raised

However, repeated Russian attacks on the Ukraine’s section of the network have put such supplies under threat.

Ukrainian oil pipeline operator Ukrtransnafta has told Transneft and Russian oil producers using the southern leg of the pipeline that it will increase transit tariffs by 25% from 1 June and by a further 24% from 1 August, according to UK-based pricing agency Argus.

Ukrtransnafta had already increased transit tariffs last year, but the burden of that increase fell on the buyers of Russian oil in Eastern Europe that pay the Ukrainian pipeline operator directly.