At least three people have been killed and 21 injured after a homemade explosive device was detonated at an Italian restaurant in Moscow, Russian state media reports, quoting security officials.

The blast happened at about 20:00 local time (17:00 GMT) on Kudrinskaya square near the city centre.

The National Anti-Terrorist Committee said a woman carrying the explosives tried to enter the restaurant but was stopped by a security guard.

The device detonated, killing the woman, the guard and a visitor to the Balzi Rossi restaurant, which had been holding a private function.

Authorities have not said who they believe was the target, but many Muscovites will suspect a link to the war in Ukraine.

In recent years, several senior Russian military figures have been assassinated in and around the Russian capital. Moscow has blamed Kyiv for those attacks.

Initial reports said the blast happened in the establishment's kitchen but the restaurant later issued a statement saying "there was a problem outside".

The restaurant is located in one of Moscow's famous Stalin-era skyscrapers, with roads around the square briefly closed.

Dozens of cyclists had been gathering nearby for an evening ride through the city but the event was cancelled.

Video released by Russia's RIA news agency showed heavily armed law enforcement officers at the scene, which had been closed off to members of the public.