A parcel bomb blast at a residential building in Monaco has seriously injured a Ukrainian oligarch and two other members of his family, according to French and Ukrainian media reports.

The other two victims were Vadym Yermolaiev's partner and thirteen-year-old son, the reports say. The parents are in critical condition.

The blast occurred shortly before 21:00 local time (19:00 GMT) on Rue Révérend Père Louis Frolla, near the border with France.

Monaco's government said the explosion was caused by a parcel bomb, while Minister of State Christophe Mirmand told AFP the explosive device appeared to contain bolts and pellets.

He said it was a "deliberate explosion" and police were investigating.

Le Figaro said video surveillance images of the moments before the attack showed a man dropping a backpack in the lobby of a building shortly before the explosion.

The Monaco government said a suspect was seen on a video surveillance system fleeing towards France on foot afterwards.

More than 100 police and emergency personnel were deployed to the scene.

"This is the first time in history, to my knowledge, that such an act has taken place in the principality," Mirmand, the head of Monaco's government, said.

The Monaco government said the three injured people had been taken to hospital in the nearby French city of Nice.

Monaco's Prince Albert II described the incident as a "heinous crime" and "a shock to the entire Monaco community".

He said "all concerned state services are currently being mobilised" in co-operation with the relevant French authorities.

Yermolaiev is a real estate developer who left Ukraine several years ago. He was sanctioned by Ukraine in December 2023.