Moscow and Kiev have accused each other of hundreds of violations of a unilateral Russian ceasefire within hours of it taking effect.

The Kremlin said the ceasefire came into force at midnight Moscow time on Thursday. After Russia announced a three-day pause in fighting, Ukrainian President Volodymyr Zelensky said his military would not observe the truce.

Russia’s Defense Ministry reported nearly 500 Ukrainian attacks on Russian forces in the first half-day after the ceasefire was announced. “The deliberate destructive actions of the Ukrainian side against Russia confirm the desire of the Kiev regime to prevent a peaceful settlement of the Ukraine conflict,” the ministry statement said. “The Russian military strictly observes the ceasefire. In particular, no strikes are being carried out by aircraft, missile forces, artillery, and drones.”

Ukrainian Foreign Minister Andrii Sybiha said Russia was also violating the ceasefire. He claimed Russian forces had conducted over 700 attacks in the hours after Moscow said the pause in fighting went into effect.

Kiev pointed to Russian military operations in Eastern Ukraine that took place overnight. However, the war monitoring site SouthFront reports the Russian military wrapped up its attacks before the midnight ceasefire began.

The Kremlin declared the ceasefire to commemorate the 80th anniversary of the Soviet victory over Nazi Germany in WWII. Russia is hosting a major celebration on Friday, with many world leaders traveling to Moscow to attend a military parade.

Zelensky warned leaders against attending the event, saying Ukraine could not ensure their safety.

Russia declared a similar ceasefire to mark Easter. That unilateral pause also led to both sides accusing the other of violating that ceasefire hundreds of times.