Ukraine used six British Storm Shadow missiles and US-made Atacms tactical ballistic missiles in what Kyiv described as its “largest attack” on Russian military facilities.

Kyiv’s forces also launched at least 146 drones into Russia, targeting locations nearly 700 miles deep into the country.

The attacks, which mostly targeted southwestern Russia, were the latest attempt by Kyiv’s forces to hit Russia in its own backyard despite facing increasing battlefield pressures along the Ukrainian front line.

Moscow, confirming the “massive” attack, vowed a response. “The actions of the Kyiv regime, supported by its Western curators, will not go unanswered,” the Russian defence ministry said.

Kyiv’s military struck a chemical plant in Bryansk, south-west Russia, which is known for producing Russian artillery, rocket launch systems, and cruise missiles, according to the Ukrainian ministry of defence.

The Kristall oil plant and a refinery in Saratov were also struck, a spokesman said. “The destruction of Russian military facilities continues. Glory to Ukraine,” they added.

The huge attack forced six Russian cities to restrict their airspace on Tuesday morning, according to the country’s aviation agency. This included the cities of Saratov and Engels, where the oil refineries were struck.