A teenager was arrested on suspicion of attempted murder Sunday after a 6-year-old child was thrown from the 10th floor viewing platform at London's Tate Modern art gallery, police said.

The Metropolitan Police said officers and paramedics found the injured child on a fifth-floor roof of the Tate. He was taken by air ambulance to a local hospital, where he was listed in critical condition, police reported in a statement.

"A 17-year-old male had remained with members of the public on the10th floor viewing platform," the statement said. "There is nothing to suggest that he is known to the victim."

The outdoor viewing area and a rooftop bar sit atop the Tate Modern, which is Britain's national gallery of international modern art.  Visitors to the open terrace get free panoramic views of the British capital.

Located on the south side of the River Thames, the gallery was the U.K.'s most popular tourist attraction in 2018, generating 5.9 million visits, according to the Association of Leading Visitor Attractions.