London police temporarily evacuated the famous TrafalgarSquare in the city center on Saturday.

The authority did not initially name a reason, but gave the all-clear after a few minutes. “The case is now closed and the place will be reopened in due course,” the police wrote on Twitter. The fire brigade was also on site, but no rescue services.

Eyewitnesses reported a loud detonation. Nearby hotels have also been evacuated. A reporter from the Canadian broadcaster Global News reported that it was a controlled demolition. The police examined a suspicious vehicle. There was no confirmation of this at first.