"It has to do with the general situation. Security reasons are of utmost importance," said Kremlin spokesman Dmitry Peskov, quoted by Russian news agencies.

The parade was meant to be the highlight of Russia's Navy Day, which falls on the last Sunday of July each year and honours the country's sailors.

But local authorities in the coastal city of Saint Petersburg, where the warships and submarines were scheduled to pass, said on Friday the parade had been cancelled without giving a reason.

Russian President Vladimir Putin -- who re-established Navy Day in 2017, nearly four decades after it was cancelled in Soviet times -- did not show up in person this year for the first time.

Instead, he appeared in a video message hailing the "bravery" and "heroism" of Russia's sailors participating in the offensive in Ukraine.

Russia, which launched its military operation on Ukraine in February 2022 with daily bombardments of its neighbour, has faced retaliatory Ukrainian drone strikes on its territory in recent months.

The Russian defence ministry said on Sunday that 100 Ukrainian drones were downed overnight.

At least 10 of them were intercepted not far from Saint Petersburg and a woman was wounded, the governor for the northwestern Leningrad region, Aleksandr Drozdenko, said on Telegram.

That drone assault also disrupted operations at Saint Petersburg's Pulkovo airport, delaying dozens of flights, the facility's authorities said.