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.