Authorities in Monaco are investigating an explosion outside a residential building that seriously injured three people, amid reports that a prominent Ukrainian businessman may have been the intended target.

The blast occurred at about 9 p.m. on Monday near the entrance of a residential property close to the French border. Officials believe an explosive device was deliberately detonated before the suspected attacker fled into neighboring France.

According to multiple media reports, Ukrainian construction magnate Vadym Yermolaiev was among those injured in the explosion. Ukrainian news outlet Ukrainska Pravda reported that Yermolaiev was placed under Ukrainian sanctions in 2023 over alleged business ties to Russia.

Monaco’s Minister of State, Christophe Mirmand, said a woman sustained life-threatening injuries and was transferred to a hospital in Nice for treatment.

Her partner and a 13-year-old child also suffered injuries but were reported to be in less critical condition and remain hospitalized.

Authorities have not officially identified the victims or confirmed whether Yermolaiev was the intended target.

Police launched a large-scale search on Tuesday across Monaco and nearby areas in France as investigators worked to identify and locate the suspect.

Law enforcement agencies from both Monaco and France are coordinating the investigation, with officials saying the motive behind the attack remains under investigation.

The explosion has raised security concerns in the principality, where targeted attacks of this nature are uncommon.

Investigators are continuing to examine forensic evidence from the scene while appealing for witnesses and reviewing surveillance footage as they seek to determine who carried out the attack and why.