The explosion occurred around 6 p.m. Saturday local time, but the circumstances are still unclear.
It is clear that the restaurant, an Italian fine-dining restaurant, was closed to the public at the time due to a private banquet, but who had booked the place is unclear.
According to Russia's National Anti-Terrorism Committee, a woman tried to enter the premises with a homemade bomb, but was stopped by a security guard.
Called a terrorist act
The state-controlled Russian business newspaper Kommersant reports that the guard became suspicious of the woman, who had allegedly come to the restaurant to deliver a package she described as a gift. The bomb was allegedly detonated when the guard checked on her. The woman, the guard and an unnamed guest were killed.
Investigators suspect the bomb was detonated remotely and that the woman was unaware of the contents of the package, the newspaper writes. Moscow mayor calls the incident a terrorist act, but does not point to anyone responsible.
According to reports in independent Russian exile media, a birthday party for a high-ranking general was taking place in the restaurant. However, this information is still unconfirmed. The pro-Kremlin newspaper Izvestia writes that it was a wedding party and that two of the injured died in hospital.
Toned down
The restaurant is located on Kudrinskaya Square, where one of Moscow's "seven sisters", the so-called Stalin skyscrapers, rises.
The restaurant's head chef Carmine Aliferi initially downplayed the incident.
"Everything is fine with us, our restaurant and kitchen are in excellent condition. There were only minor problems outside the restaurant," Aliferi wrote on Instagram, in a post that has since been deleted.
The restaurant is closed on Sunday, according to the website.
