(CNN) Julian Cadman, the 7-year-old Australian-British boy who was reported missing in the aftermath of the Barcelona attack, has been confirmed dead by his family.

Cadman, who was in Barcelona to attend a family wedding, was with his mother on Las Ramblas when the van plowed through the crowds on Thursday, killing 13 and injuring 120.

Julian's family confirmed that he had been killed in a statement Sunday.

The Catalan emergency services urged people via Twitter to avoid going out or undertaking any other type of movement that is not "strictly necessary."

The Catalan emergency services urged people via Twitter to avoid going out or undertaking any other type of movement that is not "strictly necessary."

A woman cries as she speaks on her phone in Barcelona on August 17.

A woman cries as she speaks on her phone in Barcelona on August 17.

Medics and police tend to injured people near the scene of the attack in Barcelona.

Medics and police tend to injured people near the scene of the attack in Barcelona.

Police accompany clients of a store outside a cordoned off-area of Barcelona. Las Ramblas is especially crowded in the summer, the height of tourist season. The promenade passes by kiosks, flower sellers, cafes and bars.

Police accompany clients of a store outside a cordoned off-area of Barcelona. Las Ramblas is especially crowded in the summer, the height of tourist season. The promenade passes by kiosks, flower sellers, cafes and bars.

The van that plowed into the crowd in Barcelona is towed away from Las Ramblas on August 18.

The van that plowed into the crowd in Barcelona is towed away from Las Ramblas on August 18.

Pigeons fly over a Barcelona crowd that gathered for a minute of silence on August 18.

Pigeons fly over a Barcelona crowd that gathered for a minute of silence on August 18.

A man embraces a police officer in Cambrils on August 18. Earlier in the day, officers had engaged in a shootout with five attackers who drove a car into several pedestrians. All five were shot dead by police, four of them by one officer, police said.

A man embraces a police officer in Cambrils on August 18. Earlier in the day, officers had engaged in a shootout with five attackers who drove a car into several pedestrians. All five were shot dead by police, four of them by one officer, police said.

Two women cry at the street memorial in Barcelona on Friday, August 18.

Two women cry at the street memorial in Barcelona on Friday, August 18.

A makeshift memorial pays tribute to those who were killed in a terror attack in Barcelona, Spain, on Thursday, August 17. A van rammed into a crowd of people near the popular tourist area of Las Ramblas. Early the next morning, a group of five attackers drove into pedestrians in the Spanish town of Cambrils, about 75 miles south of Barcelona.

A makeshift memorial pays tribute to those who were killed in a terror attack in Barcelona, Spain, on Thursday, August 17. A van rammed into a crowd of people near the popular tourist area of Las Ramblas. Early the next morning, a group of five attackers drove into pedestrians in the Spanish town of Cambrils, about 75 miles south of Barcelona.

"Julian was a much loved and adored member of our family," said the statement released by the Australian Department of Foreign Affairs and Trade.

"As he was enjoying the sights of Barcelona with his mother, Julian was sadly taken from us.

"He was so energetic, funny and cheeky, always bringing a smile to our faces. We are so blessed to have had him in our lives and will remember his smiles and hold his memory dear to our hearts.

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"We would like to thank all those who helped us in searching for Julian. Your kindness was incredible during a difficult time.

"We also acknowledge we are not the only family to be affected by the events, our prayers and thoughts are with all people affected."

The boy's mother was injured in the attack and taken to a hospital, where she told hospital workers before losing consciousness that her son had been with her, according to Francisco Jimenez, coordinator of SOS Desaparecidos -- a nonprofit organization that shares information about missing people.

The Catalan interior ministry issued a statement Sunday clarifying that Julian "had never been lost," but officials did not include him among the victims until his identity was confirmed and his family was notified.

British foreign secretary: Boy's death a 'tragedy'

British Foreign Secretary Boris Johnson sent his condolences to Cadman's family on Twitter.

"I send my sincerest sympathies to the family of Julian Cadman and all those who loved him. His death is a tragedy.

"The FCO, our Australian colleagues & the Spanish authorities continue to do all we can to support his family at this deeply distressing time."

A spokesman for the British Foreign Office said the department was assisting the family. "His family have our deepest sympathies at this very difficult time. Our staff are doing all they can to support them, working with our Australian colleagues and the Spanish authorities."