CCTV footage shows a man dressed in a black bucket hat and jumper dumping a backpack in the foyer of an apartment block before vacating the scene hastily.

The two adults injured in the attack, including Ermolaev, were taken to the Pasteur Hospital in Nice.

The younger victim was reportedly treated at the scene.

Ukrainian-born businessman Vadim Ermolaev, who is reportedly among those fighting for his life after the suspected bomb explosion, is one of the wealthiest oligarch figures to emerge from the country's industrial sector.

Ermolaev is described in public sources as a Cypriot-based businessman of Ukrainian origin. He is a real estate developer, best known for his role in developing projects in the city of Dnipro.

He is associated with the Alef Group, a commercial and industrial conglomerate founded in 1997, with interests spanning real estate, manufacturing, agribusiness, alcohol production and trade.

Public estimates of his wealth have varied widely over time, with figures ranging from around $173 million to more than $800 million.

According to publicly available reports, Ermolaev obtained Cypriot citizenship in 2019 and later renounced his Ukrainian citizenship.

He is under sanctions in Ukraine.

A local has explained how she thought a fireworks display was going off at the time of the attack.

Marine Cotta told BFMTV: "I thought to myself, 'Oh, it's just another firework', and shortly after I started receiving messages to see how I was doing."

She said she found out about the incident on social media.

Marine added: "I could hear the police, the alarms, the firefighters and then I thought, 'Okay, something's happening.'"

A large emergency response presence remains in place after the explosion.

A cordon is in place and police are working to locate the suspect.

One of the victims of an explosion in Monaco is as a billionaire Ukrainian oligarch, according to local reports.

Three people - all believed to be Ukrainian - have been injured in the explosion shortly after 9pm on Monday, June 29 on Rue du Révérend Père Louis Frolla.

One victim was named locally by Monaco Matin news outlet as Vadim Ermolaev, one of Ukraine's wealthiest men. It is understood that he fled the country after the latest bout of conflict with Russia.

Read the full story here.

The suspect remains at large following the explosion in Monaco but he has been tracked using security cameras making his way through Monaco and to Beausoleil.

Police officers from the Nice Anti-Crime Squad (BAC), as well as emergency response units from Nice and Menton, have been sent to reinforce the Beausoleil area.

Monaco's Minister of State Christophe Mirmand told AFP that the explosive device is believed to have contained "bolts and shot" which would have been designed to cause maximum injuries.

"The explosive device likely contained bolts and pellets," he said. "The police are currently gathering evidence."

French rescue teams are helping Monaco emergency services following the explosion.

"Following the explosion this evening in Monaco, French rescue teams are on site to reinforce the operation and police cooperation has been put in place to find the perpetrator who fled," a source close to Interior Minister Laurent Nunez said, reported TF1.

Monaco's head of state, Christophe Mirmand says: "The police are currently gathering evidence.

"This is the first time in history, to my knowledge, that such an act has occurred in the Principality."

Charles Ange Ginésy, President of the Alpes-Maritimes Council, wrote on X: "In the face of the attack that occurred in Monaco this evening, I express my deep solidarity with the victims, their families, and the people of Monaco.

"I also extend my support to the security forces and emergency services engaged on the ground."

The victims are a couple in their 50s and 60s, both in critical condition, and a 13-year-old boy "likely connected to the couple" and less seriously injured, Mirmand said.

Local sites earlier reported they all came from the same Ukrainian family.

Monaco's Minister of State, Christophe Mirmand, told AFP: "This is likely an attack."

The explosive device likely contained bolts and shot, he added. "

The police are currently investigating... This is the first time in history, to my knowledge, that such an act has occurred in the Principality."

The suspect ran off in the direction of Beausolei which is just over the border in France, says a British resident in Monaco.

Talking to The Mirror she explained: "The road where the explosion happened is about 20 minutes away from where we are and he has gone to the neighbouring town of Beausolei which is just over the border into France basically.

"So I imagine has has just disappeared into France. A lot of people live there and maybe spend their lives in Monaco because it is cheaper there."

A British resident living in Monaco has told of the "commotion" at the police station following the explosion.

She told The Mirror: "We live next door to the police station so we are overlooking it. It all began at around 9pm when we saw lots of police in the street. First of all we heard a big commotion outside and then there was a procession of police cars heading off.

“Everything is on high alert at the police station. There are now two armed police outside who are being ultra-cautious, they are checking everyone who is going past.”

According to local reports the suspect fled towards the neighbouring town of Beausoleil, which the Brit explained “is just over the border into France”.

They added: “I imagine he has just disappeared into France.”

National Councillor and lawyer Régis Bergonzi shared a photo from the scene saying "we stand with the victims of this tragedy".

He wrote on Instagram: "Big explosion in Monaco tonight near plaza des Moulins, after our legislative session.

"We all stand with the victims of this tragedy, their families, and our emergency services—firefighters and police officers—who responded in record time to provide assistance."

Monaco prosecutor Thibault Stéphane told Le Figaro that two of the victims are in critical condition. He added that bomb disposal experts and judicial police officers are on the scene.

The site also reported that the victims were Ukrainian and all from the same family.

According to a police source speaking to BFMTV, the "red plan" has been activated in Monaco.

The red plan is "a pre-established action strategy for a sudden event resulting in, or likely to result in, numerous casualties. It allows for a gradual increase in resources depending on the number of victims", according to the website of the Principality of Monaco.

Armed police can be seen in the street following the explosion on Rue Révérend Père Louis Frolla in Monaco.

Police have reportedly said a man was seen leaving two bags outside the building at around 9pm before the explosion went off.

The incident occurred in a residential building on Rue du Révérend Père Louis Frolla.

Firefighters are at the scene including a crew from the Alpes-Maritimes are who have been called in as reinforcements.

A suspect is reported to have fled on foot towards Beausoleil shortly before the explosion as people were entering the building.

A man is suspected of leaving a backpack by the doors of a building at about 9pm on Rue Révérend Père Louis Frolla, in Monaco.

The incident has been described by the local government as a "deliberate" act.

Officials say three people have been injured.

Two of them are said to have been seriously hurt.