A Russian drone attack has killed at least two people and injured 19 in the northern Ukrainian city of Sumy, prompting President Volodymyr Zelensky to call for a major upgrade of anti-aircraft defences.
An official building and two residential buildings were damaged in an attack carried out with four drones, the Sumy regional administration said on the messaging app Telegram.
Images posted by Ukraine's state emergency service showed mangled buildings and courtyards scattered with debris as rescue workers tackled a fire.
"Unfortunately, our country does not yet have a sufficient number of high-quality air defence systems to protect our entire territory and shoot down all enemy targets," Mr Zelensky said in his nightly video address.
"We will do everything possible and impossible to make our air defences the strongest."
Ukraine, he said, needed to protect its own territory and "in future become the basis of a European air shield. This is absolutely necessary and absolutely possible."
He said Ukrainian air defences had downed more than 3,000 targets of various types over the 16 months of war.
Another air-raid alert was declared in the Sumy region several hours after the morning strike.
Kyiv's military had earlier reported shooting down 13 of 17 Iranian-made Shahed drones launched by Moscow overnight in a separate attack on several parts of the country.
Russia, which launched its full-scale invasion of Ukraine in February 2022, has stepped up air strikes against Ukraine in recent weeks, and Ukraine has launched a counteroffensive to try to retake occupied territory.
Ukrainian officials have said gains are being made in the south and east over the past week in difficult fighting to dislodge Moscow's heavily entrenched forces.
The news on Kyiv's fightback comes as Russia's security service (FSB) claimed it had foiled an assassination attempt on the head of Crimea, a southern peninsula annexed by Russia in 2014.
Ukraine's troops, which have faced intense resistance in their counteroffensive launched last month, have urged Western allies to send more military support.
"Last week was difficult on the front line. But we are making progress," Mr Zelensky said. "We are moving forward, step by step!"
Deputy Defence Minister Hanna Malyar noted that Ukrainian forces over the past week recaptured 9sq/kmin the east and 28sq/km in the south.
Ukraine's forces have taken back over 158sq/km in the south since the start of the counteroffensive, Ms Malyar said.
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Russian forces are also on the offensive, and in recent days launched new assaults towards Svatove, in the eastern Luhansk region.
Kyiv's troops have come up against heavily entrenched Russian defensive positions both along the southern and eastern fronts.
Ms Malyar said Ukrainian troops were fighting "fierce" battles around the eastern flashpoint city of Bakhmut.
Ukraine's counteroffensive is an extremely difficult operation and it is "not a surprise" that it is not progressing at speed, a top NATO commander Admiral Rob Bauer has said.
"Ukraine did not reach its goals in any of the sectors," Russian Defence Minister Sergei Shoigu said, claiming that nearly all Leopard tanks provided by Poland and Portugal had been destroyed.
Mr Shoigu and the conventional army faced a serious challenge last month when the head of the Wagner mercenary group led his forces in a rebellion against Moscow's top military brass.
In his first comments addressing the short-lived mutiny, Mr Shoigu has said the rebellion "did not affect the operations of the troops."
"The plans failed primarily because the personnel of the armed forces showed loyalty to their oath and military duty," he said.
Following the rebellion, the Kremlin gave Wagner fighters the choice of signing contracts with the Russian defence ministry, returning to civilian life or going into exile in Moscow-allied Belarus.
Russia however said there was no need for further mobilisation to replace the Wagner troops that left the battlefield.
Kyiv is fighting to try to recapture its territories in the east and south, including the Crimea peninsula, annexed by Russia in 2014.
In Crimea, the FSB said it had foiled an attempt on the life of the Moscow-installed head of Crimea, Sergei Aksyonov.
The FSB said it had detained a suspect - "a Russian national born in 1988 who had been recruited by officers of Ukraine's Security Service (SBU)".
It added that the suspect was held while "removing the explosive device from its hiding place".
Increased attacks on Russian-occupied territories preceded the highly-expected fightback, which Ukraine launched last month after accumulating Western-made weapons.
Ukrainian officials have expressed frustration at the slow deliveries of weapons promised by the West.
