At least 12 people were killed and 39 others injured after Ukraine launched a major drone attack on the Russian city of Nizhnekamsk in Tatarstan on Monday, local authorities said.

The attack targeted both industrial and civilian facilities in the city, according to the press service of Tatarstan head Rustam Minnikhanov.

Authorities described the strike as 'massive', but did not immediately provide further details about the extent of the damage or the specific facilities hit.

Nizhnekamsk Mayor Radmir Belayev expressed grief over the casualties, saying, 'This is a tremendous pain for all of us.' A period of mourning has been declared across Tatarstan.

The attack comes amid a sharp escalation in aerial strikes between Russia and Ukraine, with both sides increasingly using drones and missiles to hit targets deep inside enemy territory.

Ukraine has stepped up its long-range drone campaign against Russian energy infrastructure in recent months, frequently targeting oil facilities, refineries, warehouses and other critical sites.

Kyiv has said the strikes are intended to put pressure on Moscow and force Russian President Vladimir Putin to negotiate an end to the war.

Russia's Defence Ministry said more than 450 Ukrainian drones were intercepted by Russian air defences overnight. Independent verification of the figure was not immediately available.

The latest attack also comes as Russia continues its own large-scale aerial campaign against Ukraine.

Last week, a combined Russian drone and missile strike on Kyiv killed 21 people, while five people were killed in a Russian artillery attack in Kharkiv, near the front line.

The intensifying attacks have increasingly affected civilian areas and critical infrastructure as both countries' air defence systems come under growing pressure.

The United Nations recently said June was the deadliest month for civilians in Ukraine since April 2022, with 1,396 people killed and 7,978 injured.

As the frontlines remain largely static, the escalating long-range strikes are increasingly shifting the impact of the conflict beyond the immediate battlefield, raising concerns over mounting civilian casualties on both sides.