Russia launched 479 drones at Ukraine in the biggest overnight drone bombardment of the three-year war, the Ukrainian air force said on Monday, as the Kremlin presses its summer offensive against the backdrop of direct peace talks.

As well as drones, 20 missiles of various types were fired at different parts of Ukraine, according to the air force, which said the barrage targeted mainly central and western areas of Ukraine.

Ukraine’s air force said its air defences destroyed 277 drones and 19 missiles in mid-flight on Sunday night, claiming that only 10 drones or missiles hit their target. Officials said one person was injured.

It was not possible to independently verify the claims.

A recent escalation in aerial attacks has coincided with a renewed Russian battlefield push on eastern and north-eastern parts of the roughly 1000-kilometre front line.

Ukraine’s President Volodymyr Zelenskyy said late Sunday that in some of those areas “the situation is very difficult”. He provided no details.

Ukraine is short-handed on the front line against its bigger enemy and needs further military support from its Western partners, especially air defences. But uncertainty about the US policy on the war has fuelled doubts about how much help Kyiv can count on.

Two recent rounds of direct peace talks between Russian and Ukrainian delegations in Istanbul have yielded no significant breakthroughs beyond pledges to swap prisoners as well as thousands of their dead and seriously wounded troops.

Russia’s aerial attacks usually start late in the evening and end in the morning, because drones are harder to spot in the dark.

Russia has targeted civilian areas of Ukraine with Shahed drones during the war. The attacks have killed more than 12,000 Ukrainian civilians, according to the United Nations. Russia says it targets only military targets.

Ukraine has developed long-range drones that continue to strike deep inside Russia.

Russia’s Ministry of Defence said on Monday that it shot down 49 Ukrainian drones overnight over seven Russian regions.

Two drones hit a plant specialising in electronic warfare equipment in the Chuvashia region, located more than 600 kilometres east of Moscow, local officials reported.

Alexander Gusev, head of Russia’s Voronezh region, said that 25 drones had been shot down there overnight, damaging a gas pipeline and sparking a small fire.

The Ukrainian General Staff claimed special operations forces struck two Russian fighter jets stationed at the Savasleyka airfield in Russia’s Novgorod region located some 650 kilometres from Ukrainian border.

The statement did not say how the planes were struck.