Monaco authorities detain then release a person in their probe of this week's explosion

A view of a hospital where, according to reports, three people injured by an an explosive device in Monaco a day before, are being treated, in Nice southern France, Tuesday, June 30, 2026. (AP Photo/Philippe Magoni)

MONACO — Monaco authorities said a person was arrested but later released Wednesday as they “very actively” pursue their probe of an explosion that reportedly wounded a Ukrainian tycoon with ties to Russia and two other people.

A statement from the Mediterranean principality’s prosecutor general said the person is a foreign national and was detained in Monaco in the morning.

They were held in police custody “as further checks were deemed necessary” before being released in the afternoon, it said, giving no further information about the person or why they aroused suspicion.

The explosion at an apartment building entrance in Monaco occurred late Monday. Monaco authorities haven’t identified any of the injured but said they were a family and that they appeared to have been specifically targeted.

Media reports identified Ukrainian construction tycoon Vadym Yermolaiev as being among the injured. He has said he renounced his Ukrainian citizenship nearly a decade ago, and he was targeted by Ukrainian sanctions in 2023 for ties to Russia. A woman and a child were also hurt.

The prosecutor’s statement said the child has been interviewed in neighboring France but that the other two victims are still not in a condition to be questioned. One of them is critically injured and their life remains in danger, it said.

It described the blast as an attempted assassination and said French authorities are assisting the investigation. Analysis of the explosive device and work to identify the bomber is ongoing, it said.

It was not clear why the family was targeted or by whom.

Russia has a long history of targeting its enemies abroad, and Western intelligence officials have recently said that a campaign of targeted killings has ramped up since Russian President Vladimir Putin’s 2022 invasion of Ukraine.

Ukraine is also believed to have carried out attacks and targeted killings of Russian figures in the course of the war, although those attacks have largely been confined to Ukrainian or Russian territory.

The attack shocked the country on the Mediterranean coast, one of the world’s smallest sovereign states known for its high concentration of wealthy residents. Monaco’s Prince Albert II described it as “an odious act” and said all public services were mobilized to ensure security.

The Associated Press