The death toll from a barrage of Russian drones and missiles that struck several districts of Kyiv early on Thursday morning has risen to 26, including three children, while 159 others were wounded, officials said. The attack brought down an apartment block.

A six-year-old boy and his mother were among the dead, as more than two dozen locations across the Ukrainian capital were hit.

Ukraine’s interior ministry said three children had died and 16 were among the wounded. Kyiv’s mayor said it was the biggest number of children hurt in one night since the full-scale war began.

Russian attacks have continued despite US President Donald Trump’s threat to impose tougher sanctions on Moscow if Vladimir Putin does not agree to a ceasefire by 8 August.

The toll was revised after “rescuers retrieved 10 bodies from the rubble of the residential building in Sviatoshynsky district, including the body of a two-year-old child”, Ukraine’s interior ministry posted on Telegram.

“Both Russia and Ukraine must negotiate a ceasefire and durable peace. It is time to make a deal,” acting US representative to the United Nations John Kelley told the UN Security Council on Thursday. “President Trump has made clear this must be done by 8 August.”

The high-pitched hum of Russian drones could be heard for hours over the city, interrupted by the occasional loud thunder clap of a missile strike.

Russia launched 309 drones and eight cruise missiles during the night, according to Ukraine’s air force. And although officials say air defences did manage to destroy many of them, there were numerous hits including from cruise missiles.

A red-orange glow indicated destruction on the ground.

These were the biggest airstrikes since Trump brought forward an earlier deadline to Putin. The threat of more US sanctions appears to have done little to persuade the Russian president to change course.

Meanwhile, Russia claimed further success on the battlefield, declaring that it had captured the strategically important hilltop town of Chasiv Yar in the eastern Donetsk region.

Ukraine denied it had fallen, however, and military analysts said fighting there was continuing.

Three of the fatalities in Kyiv were at the site of the residential apartment block.

“An entire entrance was destroyed. Rescuers are clearing the rubble,” said Ukraine’s interior minister Ihor Klymenko.

President Volodymyr Zelensky said the capital was the focus of Russia’s overnight attacks.

“The world has yet again seen Russia’s response to our, America’s and Europe’s desire for peace. More demonstrative murder,” he said on social media.

“This is why peace without strength is impossible.”

Kyiv’s Sviatoshynskyi and Solomyansky districts were hit hardest in the attack.

The windows of a hospital ward for children in Shevchenkivskyi district were blown out by a shockwave, Kyiv’s mayor said on Telegram.

One of the city’s higher education institutions, a school and a kindergarten were also damaged.

Foreign Minister Andrii Sybiha said it was a “horrible morning” in Kyiv, and that there are “still people under the rubble”.

Sybiha added that Trump had been “very generous and patient” with Putin, but now it was time to put “maximum pressure on Moscow” through sanctions.

Earlier in July, Trump set a 50-day deadline for the Kremlin to reach a truce with Kyiv or risk economic penalties.

On Monday, during a visit to the UK, Trump cut that deadline to “ten or 12 days”, expressing his disapproval at Putin’s actions in Ukraine, more than three years since Moscow launched its full-scale invasion of the country.

Trump didn’t say whether he felt the Russian president had been “lying” to him, but he said there was a discrepancy between Putin’s rhetoric during their one-on-one conversations and the missiles “lobbed” on Ukrainian cities.

“We were going to have a ceasefire and maybe peace… and all of a sudden you have missiles flying into Kyiv and other places,” Trump said.

Meanwhile, on the front line in eastern Ukraine, Kyiv denied Russian claims that the town of Chasiv Yar had finally fallen, after a battle for it that began in April last year.

Little remains of Chasiv Yar after 16 months of fighting, but Ukrainian reports cited military officials as saying the Russians were spreading disinformation.

Open-source intelligence project DeepState suggested that the Russians had taken control of eastern and northern parts of Chasiv Yar, but fighting was still going on in other areas.

Controlling the high ground that it sits on would give Russia a significant vantage point to target the big cities of the Donetsk region to the west, including Druzhivka, Kramatorsk and Sloviansk.

Ukrainian forces have faced superior Russian manpower on the front lines throughout the war, but reported shortages in the east have left another key Russian target increasingly vulnerable.

The town of Pokrovsk lies about 60km (37 miles) to the south-west of Chasiv Yar and is described as the hottest spot on the front line at this point of the war. Analysts are concerned that the thousands of Ukrainians defending the city could be at risk of encirclement from Russian troops.