A leading Russian military blogger was killed Sunday in an explosion at a cafe in Russia's second-largest city of Saint Petersburg, the Interior Ministry said.

"One person was killed in the incident. He was military correspondent Vladlen Tatarsky," the ministry said on messaging app Telegram.

"Sixteen people were injured," it added.

The TASS news agency quoted a law enforcement source as saying the blast was "caused by an improvised explosive device hidden inside a statue given to Tatarsky as a gift."

Tatarsky, whose real name is Maxim Fomin, has more than 500,000 followers on Telegram and is in favour of Russia's campaign in Ukraine.

The explosion occurred at "Street Food Bar No. 1" in the city center.

A group called Cyber Front Z, which refers to itself on social media as "Russia's information troops," said it had hired out the cafe for the evening.

"There was a terrorist attack. We took certain security measures but unfortunately they were not enough," the group said on Telegram.

"Condolences to everyone who knew the excellent war correspondent and our friend Vladlen Tatarsky," it said.

Tatarsky, 40, came from the Donetsk region in eastern Ukraine, which Russia claims to have annexed and which is currently mostly controlled by Russian troops.

The Interior Ministry said police were called to the scene of the blast at 6:13 p.m. and investigators were working at the scene.