Major General Andrei Sukhovetsky, a top officer in the Russian army, has been killed in fighting in Ukraine.
Russia said around 500 of its soldiers have been killed since it invaded neighbouring Ukraine last week, while 1,600 others have been injured. British officials said the figures were likely to be higher.
As well as Maj Gen Sukhovetsky, two other Russian generals have reportedly been killed in the fighting.
Ukraine has not released casualty figures for its armed forces but said more than 2,000 civilians have died in the fighting. The UN human rights office has been able to confirm at least 331 civilian deaths and more than 600 injuries.
Cities have been bombarded with artillery and missiles, heavy fighting has taken place across the country and more than one million Ukrainians have fled across the border during the first 10 days of the war waged by Russia.
Experts said the death of Maj Gen Sukhovetsky will be a bitter blow for Mr Putin. Here is what we know about the top military figure:
Who was he?
Maj Gen Sukhovetsky was the commanding general of the Russian 7th Airborne Division.
The 47-year-old was also a deputy commander of the 41st Combined Arms Army.
The paratrooper was by far the most senior Russian figure to have been killed in the conflict when his death was announced on Thursday.
What was his military career?
The 47-year-old went to a military academy and kicked off his career as a platoon commander, before rising through the ranks to take a number of leadership positions - including chief of staff of the Guards airborne assault unit.
He took part in Russia’s military campaign in Syria and was reportedly decorated for his role in the annexation of Crimea.
The general had also reportedly been involved in campaigns in Abkhazia and the North Caucasus.
He was a respected paratrooper who was practised in missions in “hostile territory”.
How did he die?
His death was confirmed by a local officers’ organisation in the Krasnodar region in southern Russia, who did not share information on how he was killed.
A military source said he had been killed by a sniper.
His death was announced on Thursday and was said to have happened earlier in the week.
What have the reactions been to his death?
Sergey Chipilev, a deputy of the Combat Brotherhood Russian veterans group, wrote on social media: “With great pain, we learned the tragic news of the death of our friend, Major General Andrey Sukhovetsky, on the territory of Ukraine during the special operation. We express our deepest condolences to his family.”
Others pointed to what it could mean for Mr Putin and the Russian invasion.
Christo Grozev from investigative journalism website Bellingcat said his death would be a “major demotivator” for the Russian army.
