A blast near an upscale restaurant in central Moscow killed three people and injured at least 21 others on Saturday evening, according to authorities. Officials said the explosive device was homemade and was being carried by a woman.

Authorities said the woman had tried to enter a private event at the restaurant but was refused by a security guard. The explosion happened nearby, turning what had been a busy evening area into the scene of a major emergency response.

Early reports indicated that at least 21 people were hurt in addition to the three fatalities. Investigators were working to establish the full sequence of events and confirm details about the device and the circumstances leading up to the blast.

The incident is likely to raise fresh security concerns around private gatherings and public venues in Moscow. Further updates were expected as authorities continued their investigation and checked on the condition of those injured.