A SEARCH was under way today for a suspect who fled on foot after an explosive device injured three people, including a Ukrainian tycoon, at an apartment building in Monaco.

Prosecutor Stephane Thibault said the suspect had acted alone and remained at large, with the motive unclear.

Police have opened an attempted murder investigation but are not treating the incident as terrorism-related.

One of the three injured, a woman, remains in life-threatening condition, while a man and a 13-year-old boy are no longer in danger, Mr Thibault said.

The explosion occurred around 9pm on Monday as the family returned home, with surveillance footage showing the suspect had walked around the area several times while waiting for the victims.

Monaco’s Minister of State Christophe Mirmand said: “It appears that the family was specifically targeted.”

The victims were “apparently returning home peacefully” before being “caught in the explosion as they crossed the threshold of their apartment building,” he added.

Authorities do not yet know whether the family had previously received threats.

Media reports identified Vadym Yermolaiev, a Ukrainian-born construction tycoon originally from Dnipro, as among the injured.

Ukrainian news site Ukrainska Pravda said he was sanctioned by Kiev in 2023 for allegedly having ties to Russia.

Mr Yermolaiev built his fortune through the Alef Group, a holding with interests in property, manufacturing and agriculture, leading projects that reshaped parts of Dnipro’s city centre.

He renounced his Ukrainian citizenship for Cypriot citizenship in 2017 and regularly appeared in rankings of Ukraine’s wealthiest businesspeople.

The suspect was seen on CCTV fleeing on foot via the neighbouring French town of Beausoleil, wearing a black jacket, light trousers, white shoes and a black hat partly concealing his face.

Monaco’s Prince Albert II described the attack as “an odious act,” saying all the country’s services were mobilised to ensure security.

The small principality, renowned for its “tax-friendly” incentives, is widely regarded as one of the safest places in the world, thanks in part to an extensive CCTV network.

Its population of 38,000 is largely international, with only a fifth holding Monegasque citizenship.