Ukrainian President Volodymyr Zelensky has said Russian leader Vladimir Putin was behind the death of mutinous mercenary boss Yevgeny Prigozhin, who died in an unexplained plane crash with his top lieutenants last month.
Mr Zelensky, who provided no evidence to back up his assertion, made the comment in passing at a conference in Kyiv as he was asked a question about the Russian president.
"The fact that he killed Prigozhin, at least that's the information we all have, not any other kind, that also speaks to his rationality, and about the fact that he is weak," President Zelensky said.
The Kremlin says all possible causes of the crash will be investigated, including the possibility of foul play.
It has called the suggestion that Mr Putin ordered the deaths of Prigozhin and his men an "absolute lie".
Prigozhin this summer led a brief mutiny in Russia that posed the biggest challenge to President Putin's rule since he rose to power in 1999.
It prompted the Kremlin chief to accuse its authors of "treason" and a "stab in the back".
Many critics of Putin have died in unclear circumstances during his 23 years in power, or narrowly escaped dying.
Mr Zelensky also said that Russian air superiority was "stopping" Kyiv's counter-offensive, complaining of slow Western arms deliveries and sanctions on Russia.
"If we are not in the sky and Russia is, they stop us from the sky. They stop our counteroffensive," he said, calling for more "powerful and long-range" weapons.
Arms deliveries to Kyiv and new rounds of sanctions on Russia were becoming "complicated and slower", he added.
Meanwhile, Ukraine said four people have been killed and dozens injured as Russia launched a new wave of air strikes in the centre and east of the country.
"A Russian aerial bomb killed three civilians in Odradokamyanka - two women and a man. Four local residents were injured," Interior Minister Igor Klymenko said, calling the strike in the southern region of Kherson a "war crime".
Odradokamyanka is about 60km upstream of Kherson city and lies on the west bank of the Dnipro River.
In the central city of Kryvyi Rig, President Zelensky's hometown, a missile attack on a police building killed a policeman, Klymenko had said earlier.
"Rescuers of the State Emergency Service pulled out three more from under the rubble. They are in serious condition," he said.
Photos he shared from the scene showed smoke spewing from the ruins of the building as rescue workers carried an injured person to an ambulance.
Over 40 people were injured in the city, local officials said.
At least three people were injured after Russia also struck the city of Sumy in northeast Ukraine, officials said, while one man was injured by a rocket attack on Zaporizhzhia in the southeast.
"Over the past 24 hours, 93 enemy attacks on 29 towns and villages of the Zaporizhzhia region have been recorded," said Yuriy Malashko, head of the local administration.
Odesa strikes
Russia also carried out its fifth drone attack this week on the southern Odesa region, home to Ukrainian ports on the Black Sea and Danube River that are used to export grain and other agricultural products.
Russia has intensified air attacks on Ukrainian grain export infrastructure on the Danube River and in the port of Odesa since mid-July, when Moscow quit the UN-brokered deal that allowed safe Ukrainian grain exports via the Black Sea.
"During the night the Russian terrorists attacked the Odesa region for the fifth time this week," Oleh Kiper, the Odesa regional governor, said on the Telegram messaging app.
Officials said air defences shot down 16 of the 20 drones fired by Russia overnight - the Southern military command said 14 drones had been brought down over the Odesa region and two more over the southern region of Mykolaiv.
Mr Kiper said a non-residential building had been damaged by debris from a drone but gave no further details. He reported no casualties in the Odesa region.
Regional officials said Russia had also attacked the southeastern region of Zaporizhzhia and the northeastern region of Sumy with missiles, wounding several people.
Ukraine's emergency services said three people had been hurt in the Sumy region and posted a video showing rescuers pulling out an injured woman from a hole caused by the explosion.
It said in a statement that the 65-year-old woman and a 70-year-old man were rescued after a two-storey residential building was damaged.
Russia did not immediately comment on the latest attacks.
Ukraine reports some successes in counter-offensive
Earlier, President Zelensky singled out military units in the east and south for their actions against Russian troops, while other officials reported some breakthroughs in a counteroffensive to reclaim Russian-occupied territory.
The general staff of Ukraine's armed forces described a "partial success" near the eastern city of Bakhmut, long a focal point of fighting.
It said Ukrainian troops were making gradual progress in their southward advance to the Sea of Azov.
Russian accounts of the fighting said their troops had beaten back Ukrainian attacks near Bakhmut.
Reuters was not able to verify battlefield reports of either side.
Ukraine began its counteroffensive in June and has focused on retaking Bakhmut, seized by Russian troops in May, and capturing clusters of villages in the south.
They face Russian troops that are well dug in and have benefited from extensive mining operations.
Ukraine has bristled at what critics in the Western media have described as the campaign's slow pace and questionable tactics.
But US Secretary of State Antony Blinken hailed "very, very encouraging progress" during talks in Kyiv on Wednesday.
Mr Zelensky, in his nightly video address yesterday, provided few details of operations.
"Thank you soldiers for very, very effective results in destroying the occupiers," Mr Zelensky said.
"And results are precisely what Ukraine needs now from everyone."
One national guard unit fighting in the east and two in the south he mentioned included the 12th brigade, which has soldiers of the Azov brigade who last year defended the Azovstal steelworks in the city of Mariupol.
Military analysts said they had been holding Ukrainian positions in the northeast.
The general staff report said: "As a result of its assault operations, the defence forces have achieved a partial success south of Bakhmut, pushing the enemy out of and reinforcing their own positions."
Deputy Defence Minister Hanna Maliar told national television that Ukrainian forces were pressing their drive near southward from the village of Robotyne, captured last week.
Ms Maliar said that on the southern front, where Ukrainian forces are trying to sever a land bridge established by Russia between the Crimean peninsula Russia annexed in 2014, and the occupied east, "events are developing rapidly."
Russia's Defence Ministry, in its reports on the fighting, said Moscow's forces had repelled nine attempted Ukrainian advances near Klishchiivka, a village on heights south of Bakhmut seen as critical to securing control of the city.
