Authorities in Monaco are investigating what prosecutors have classified as an attempted murder after a powerful explosion outside a residential building injured seven people, including three seriously, in an attack that French media say targeted Ukrainian businessman Vadym Yermolaiev and members of his family. 

The blast, which shook the wealthy Mediterranean principality on the evening of June 28, prompted an extensive cross-border manhunt after surveillance footage allegedly showed a suspect leaving a backpack containing an explosive device at the entrance to a residential complex before fleeing the scene. The device reportedly contained bolts and metal pellets designed to maximise casualties.

The incident has attracted international attention not only because of its rarity in one of Europe's safest jurisdictions, but also because of speculation over whether the apparent target's business and political connections may have played a role. However, while a range of commentators have advanced competing theories, Monaco's authorities have not publicly linked the attack to Ukraine, organised crime or any political motive.

Initially, Monaco officials said they could not rule out terrorism. State Minister Christophe Mirmand described the explosion as unprecedented in the principality's modern history.

That assessment was later revised after investigators gathered preliminary evidence. Monaco's chief prosecutor, Stephane Thibault, announced that the case would instead be investigated as attempted murder.

"This attack cannot be classified as terrorism," Thibault told reporters, adding that investigators were concentrating their efforts on identifying and apprehending a single suspect.

According to French newspaper Nice-Matin, witnesses reported seeing a man wearing a dark shirt and a bucket hat near the scene shortly before the explosion. Surveillance cameras later reportedly tracked him into neighbouring French territory before losing sight of him. Police and gendarmerie, assisted by helicopters equipped with searchlights, conducted overnight searches, while authorities said they had not ruled out the possibility that the suspect had accomplices.

French newspaper Le Figaro reported that three people suffered serious injuries and four others sustained lighter wounds.

Although Monaco's authorities have not officially identified the victims, multiple French media outlets reported that the principal target was Vadym Yermolaiev, a Ukrainian-born businessman originally from Dnipro.

Yermolaiev built his fortune through the Alef industrial and commercial group and became one of Dnipro's largest property developers. He previously ranked among Ukraine's wealthiest businessmen, with Forbes Ukraine estimating his fortune at around $220mn in 2021.

The businessman renounced his Ukrainian citizenship in 2019 and became a citizen of Cyprus. In late 2023, Ukrainian President Volodymyr Zelenskiy imposed personal sanctions on Yermolaiev, citing his reported alcohol-related business interests in Russian-annexed Crimea. According to Nice-Matin, he had lived in Monaco for roughly a decade before the attack.

The sanctions and Yermolaiev's long business career have fuelled widespread speculation about possible motives.

Ukrainska Pravda, citing unnamed law enforcement sources, reported that investigators in Ukraine were examining whether the bombing could have been connected to fraudulent call-centre operations allegedly linked to Dnipro. The publication suggested the attack may have specifically targeted the businessman, although it did not provide documentary evidence supporting that claim.

Other public figures have advanced broader allegations. Florian Philippot, leader of the French political party Les Patriotes, wrote on social media platform X that Yermolaiev's inclusion on Ukraine's sanctions list could indicate involvement by the Security Service of Ukraine (SBU) or pro-Ukrainian extremist groups. He provided no evidence to support the assertion.

Former Ukrainian lawmaker Volodymyr Oliinyk separately claimed that Yermolaiev had allegedly financed political opponents of President Zelenskiy and said he could not exclude the possibility of political involvement. His comments likewise were not accompanied by supporting evidence.

Ukrainian blogger Anatolii Sharii also suggested the explosion was linked to disputes surrounding Yermolaiev's business interests, alleging that pressure had previously been exerted against his companies in Ukraine. Sharii did not provide evidence for his claims.

Former Ukrainian parliamentarian Spiridon Kilinkarov told Russian media outlet Ridus that the attack could instead reflect competition over financial flows allegedly generated by fraudulent call-centre schemes, arguing that business disputes rather than politics may have been the underlying motive.

None of these claims has been confirmed by Monaco's investigators, and authorities have made no public statement implicating Ukraine, Ukrainian security services or organised criminal groups.

The attack deeply shocked residents of Monaco, a microstate better known for luxury tourism, banking and the Formula One Grand Prix than violent crime.

Residents interviewed by Nice-Matin described scenes of confusion immediately after the explosion.

One 23-year-old woman said she initially believed a nuclear explosion had occurred because of the force of the blast.

"The noise was terrible. Everything was shaking. We really thought our building was about to collapse," she told the newspaper.

Another resident said she initially believed either an earthquake or a helicopter crash had occurred, adding that the first 20 minutes after the explosion passed "in a blur".

Several witnesses remarked that they had never before seen such a large deployment of police officers in Monaco.

According to Nice-Matin, Yermolaiev suffered burns and shrapnel wounds but remained conscious after being transported to hospital in Nice.

French media reported that his wife sustained the most severe injuries and underwent emergency surgery after suffering traumatic leg injuries. A 13-year-old family member reportedly sustained burns and bruising, with one of the bomb's metal bolts becoming lodged in his leg.

Medical personnel treated four other people for minor cuts at the scene.

Investigators continue to search for the suspect while examining surveillance footage and forensic evidence recovered from the site as they seek to establish both the identity of the attacker and the motive behind one of the most serious violent incidents ever recorded in the principality.