Moscow mayor Sergei Sobyanin has called a bomb attack on a restaurant in the capital a “brutal terrorist act”, but did not say who was responsible.

The blast on Saturday evening at the Balzi Rossi, an upscale Italian establishment in central Moscow, killed three people, including the female bomber, Russian state media said, citing local officials.

“Yesterday, a brutal terrorist act was committed in Moscow that claimed human lives. The victims are currently in the city’s hospitals, where they are receiving all necessary care,” Mr Sobyanin wrote on social media Sunday.

At least 21 people were wounded when the explosive device detonated at the restaurant on Kudrinskaya Square, Russia’s National Anti-Terrorism Committee (NAK) said late on Saturday, according to Russian state news agency Ria Novosti.

The woman attempted to smuggle the bomb into the establishment, but the security guard refused to let her in before the bomb exploded, reported Ria Novosti. 

The Moscow Investigative Committee said the attack was still being investigated.

An night-time aerial image shows a busy street with multiple emergency vehicles and pedestrians and cyclists looking on

The attack took place at an upscale restaurant in central Moscow. (Reuters: Anastasia Barashkova)

The woman, the guard and a customer at the Balzi Rossi Italian restaurant were killed instantly in the blast, NAK said.

As of early afternoon on Sunday, local time, there was no further information from Russian authorities, and no one had publicly claimed responsibility.

Footage released by Russian state media showed heavily armed law-enforcement officers, several ambulances and other emergency vehicles at the site.

Ukraine war link speculated

Authorities have not revealed the names of the killed or injured or those of any suspects, but unverified social media reports suggested that a top Russian military commander had been the intended target but had been unharmed.

Drones make life in Russia’s cities a ‘nightmare’

For years, people in Russia’s largest and most affluent cities were shielded from the impacts of their country’s full-scale invasion of Ukraine, but not anymore.

More than four years into a full-scale war with Ukraine, Russia this year promised better protection for high-ranking military officials after a series of assassinations and attempted killings, which it blamed on Kyiv.

Russian war bloggers, without citing any evidence, were quick to blame Ukraine for the attack. Kyiv did not immediately comment.

The Kommersant Daily suggested that the woman carrying the bomb may not have known about it, and that it had been set off remotely by someone else.

The restaurant’s website said the venue had been closed on Saturday for a private event.

AP/Reuters