Kyiv said on Monday its forces had recaptured an oil and gas drilling platform in the Black Sea that had been controlled by Moscow since 2015.

The platform is roughly half way between the Moscow-annexed Crimean peninsula and the coast of Ukraine’s southwestern Odesa region.

‘Ukraine regains control of the so-called Boyka Towers (platform),’ Kyiv’s military intelligence said in a statement.

It said it had established control of drilling platforms and rigs in what it called a ‘unique operation.’

‘During one phase of the operation, a battle took place between Ukrainian special forces on boats and a Russian Su-30 fighter jet,’ it said, claiming that Moscow’s plane was ‘hit and forced to retreat.’

It released a video of boats circulating around the oil and gas platform, before its troops are seen firing into the air.

Russia annexed Crimea and much of the surrounding waters in 2014, and has accused Ukraine of trying to attack the rig before.

Ukraine and Russia have increased attacks in the Black Sea since Moscow pulled out of a key deal ensuring the safe navigation of cargo ships.

Meanwhile, Kyiv said on Monday its forces had recaptured clutches of land in south and east Ukraine, and fought their way into a village in the Donetsk region last week.

Kyiv launched a counter-offensive against entrenched Russian positions in June but progress has been limited, spurring political debate in the West over support for Kyiv.

Deputy defence minister Ganna Malyar said Ukrainian forces had pushed back around the war-battered city of Bakhmut in the east, which was captured by Russia in May.

‘Around two square kilometres were liberated in this sector throughout the week. In total, 49 square kilometres have already been captured near Bakhmut’ since the counter-offensive began, she said.

Further south, Ukraine’s forces had battled their way into the village part of Opytne near the larger hub of Avdiivka, Malyar told state media.

Ukraine has committed the bulk of its resources to fighting along its southern front, where the military has punctured Russia’s first line of defence and captured several villages.

‘Over the past week, 1.5 square kilometres of our land were liberated. During the offensive, we had successes south of Robotyne and west of Verbove,’ Malyar said, referring to two villages in the Zaporizhzhia region.

The Kremlin claimed to have annexed Zaporizhzhia, Donetsk and two other Ukrainian regions last year, despite not having full military control over them.

Russia’s central elections commission said the pro-Kremlin United Russia party easily won local elections in those annexed territories over the weekend, in votes dismissed by Kyiv.