Russia has carried out missile strikes on Ukraine's two biggest cities - damaging apartment buildings and killing at least 18 people, President Volodymyr Zelenskyy has said.
The attacks on the capital Kyiv and second largest city Kharkiv came after Moscow shunned any deal backed by Ukraine and its Western allies to end the nearly two-year war.
The strikes also come two days after Moscow-installed officials in eastern Ukraine claimed that Ukrainian shelling had killed 27 people on the outskirts of Russian-occupied Donetsk.
In his nightly address, President Zelenskyy said Russian missile strikes killed 18 people and injured more than 130.
He also added that more than 200 sites were struck, including 139 dwellings.
Officials in Kharkiv had earlier said that eight had died in an attack on an apartment building.
The Russian barrage included more than 40 ballistic, cruise, anti-aircraft and guided missiles, officials said earlier on Tuesday. Ukraine's air force said it had intercepted 21 of them.
Russia used S-300, Kh-32 and hypersonic Iskander missiles in the attack.
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Kharkiv mayor Ihor Terekhov said the temperature in the city overnight was -7C (19F).
Lying about 18 miles (30km) from the border with Russia, Kharkiv has often felt the brunt of Russia's winter campaign of long-range strikes that commonly hit civilian areas.
The attacks keep Ukrainians on edge while the 930-mile long (1,500km) frontline has barely budged.
Both sides' inability to deliver a knockout punch on the battlefield has pushed the fighting towards trench and artillery warfare.
Analysts say the Kremlin's forces stockpiled missiles at the end of last year to press a winter campaign of aerial bombardment.
There appears to be little chance of an end to the war anytime soon.
Moscow rejects any Western-backed peace deal
Russia's foreign minister defied the United States and other Ukraine supporters at a UN meeting on Monday, ruling out any peace plan they support.
Sergei Lavrov, Russia's top diplomat, claimed that Ukrainian forces had been "a complete failure" on the battlefield and were "incapable" of defeating Russia.
Kremlin spokesman Dmitry Peskov said Ukraine committed a "monstrous terrorist act" when he accused the country of carrying out shelling which left 27 people dead in Donetsk on Sunday.
But the Ukrainian military denied it had anything to do with the attack.
Mr Peskov said Tuesday's attacks should not be seen as Moscow's response to the Donetsk strike.
He repeated the Kremlin's argument that its forces do not strike civilian areas, although there is substantial evidence to the contrary.
The Ukrainian civilian deaths have helped stir international outrage over Russia's invasion of its neighbour, and Ukrainian officials have pointed to the attacks in their efforts to secure further military aid from the country's allies.
NATO signed a $1.2bn (£950m) contract to make tens of thousands of artillery rounds to replenish the dwindling stocks of its member countries.
The contract will allow allies to backfill their arsenals and provide Ukraine with more ammunition.