Ukraine's President has fired his spy chief and top state prosecutor over allegations officials have been collaborating with Russia.
Volodymyr Zelensky abruptly issued executive orders sacking his childhood friend and head of Ukraine's powerful domestic security agency, the SBU, Ivan Bakanov and Prosecutor General Iryna Venediktova.
The furious president said he had fired the pair after it emerged that many members of their agencies had collaborated with Russia - with other agencies also accused of treason.
He said 651 cases of alleged treason and collaboration have been opened against prosecutorial and law enforcement official.
More than 60 officials from Bakanov and Venediktova's agencies are now working against Ukraine in Russian-occupied territories, he added.
Venediktova has played a key role in the prosecution of Russian war crimes.
Zelensky, in his nightly address to the nation, said: "Such an array of crimes against the foundations of the national security of the state ... pose very serious questions to the relevant leaders.
"Each of these questions will receive a proper answer."
Bakanov and Venediktova have not commented on the allegations.
It comes as Vladimir Putin 's troops have captured swathes of Ukraine's south and east during an invasion that has killed thousands, displaced millions and destroyed cities.
Vadym Skibitskyi, a spokesman for Ukrainian military intelligence, said Russia is preparing for the next stage of its offensive in Ukraine.
He said: "It is not only missile strikes from the air and sea. We can see shelling along the entire line of contact, along the entire front line. There is an active use of tactical aviation and attack helicopters.
"Clearly preparations are now underway for the next stage of the offensive."
Ukraine says at least 40 people have been killed in Russian shelling since Thursday as the war launched by Putin on February 24 intensifies.
Dozens of relatives and local residents attended the funeral of four-year-old Liza Dmytrieva on Sunday.
Liza, who had Down’s Syndrome and arthritis in one leg, tragically died after being killed by Putin's latest sickening missile strike on the city of Vinnytsia.
Her mother Irina Dmitrieva is now seriously injured and fighting for her life in intensive care.
