Russian forces launched a record aerial assault on Ukraine overnight, Ukrainian officials said, sending at least 805 drones and more than a dozen ballistic and cruise missiles across the country in an attack that killed a woman and her two-month-old son in Kyiv and wounded dozens of others.

The strikes, which Kyiv described as one of the largest of the war, targeted more than 20 cities and damaged energy and transport infrastructure, including a bridge over the Dnipro River and the offices of Ukraine’s Cabinet of Ministers. NATO allies scrambled fighter jets over Poland as allied air-defence and radar systems were placed on a heightened state of readiness, officials said.

Ukrainian authorities said the 32-year-old woman and her two-month-old son died in the Sviatoshynskyi district of the capital; rescuers pulled the child’s father from rubble with wounds. Local officials also reported a woman killed in the Sumy region and dozens injured nationwide. Mayor Vitali Klitschko said the greatest damage in Kyiv was to a nine-storey residential building, where partial collapses affected floors four through eight and rescuers were searching for additional victims.

Ukrainian defence and government sources initially acknowledged 805 strike drones and 13 Iskander cruise and Iskander-M ballistic missiles. Officials said air defences destroyed or caused 751 of the incoming drones and missiles to miss their targets, while acknowledging nine missile hits and 56 strike-drone hits at 37 locations. Pro-Russian media and channels posted higher figures, some claiming as many as 1,000 drones.

The barrage struck cities including Kyiv, Odesa, Kryvyi Rih, Kremenchuk, Khmelnytskyi, Dnipropetrovsk and Zaporizhzhia. In Kyiv, high-rise residential buildings and a nursery school were damaged and firefighters worked to douse flames at the Cabinet of Ministers building, where officials reported damage to the roof and upper floors — a first for the government headquarters since the invasion began.

Kremenchuk and surrounding areas saw multiple explosions, footage showed attacks on the Kryukovskiy bridge and disruptions to road and rail links. Officials reported damage to the dam area in Svitlovodsk and an airfield in the Khmelnytskyi region. In Odesa, authorities said sports facilities, residential buildings and other infrastructure were hit.

The Warsaw operational commander said allied fighter sorties over Poland were ‘‘of a preventive nature and are aimed at securing the airspace and protecting citizens, especially in areas adjacent to the threatened zone.’’ NATO had earlier reported that member states had taken steps to increase readiness of air-defence and radar reconnaissance systems along eastern borders.

Ukrainian Prime Minister Yulia Svyrydenko described the assault as a ‘‘massive strike’’ and urged greater international action. "The enemy terrorises and kills our people across the country every day. The world must respond to these destructions not only with words but with actions," she said, calling for tougher sanctions on Russian oil and gas and more weapons for Ukraine.

Kyiv said it struck back inside Russia during and after the attacks, targeting energy infrastructure. Ukrainian forces reported a strike on the Druzhba pipeline in the Bryansk region and attacks on oil facilities in Krasnodar region, including a fire at the Ilsky oil refinery and fires at Kavkaz port near the Kerch Strait. Russian authorities in affected regions reported evacuations at some facilities.

Russian state-affiliated outlets hailed the scale of the attack, while Ukrainian officials and Western analysts characterized the operation as one of the most intense since the start of the full-scale invasion. Debris from downed drones and missiles fell in multiple areas, compounding damage and civilian risk.

Rescue and emergency services continued search-and-rescue and firefighting operations in damaged urban areas on Sunday, and utility crews worked to restore electricity and internet service where lines had been cut. Ukrainian authorities said they would document damage and casualties for international partners and reiterated appeals for increased military and economic support to blunt further attacks.

The overnight strikes mark an escalation in the use of swarms of strike drones alongside missile salvos, testing Ukraine’s air-defence capacity and prompting increased NATO monitoring near alliance airspace. Both the extent of material damage and the full civilian toll remained under assessment as officials completed on-the-ground inspections and emergency responses across the country.