The museum was sealed off with crime-scene tape and police cars as officers tried to clear hundreds of tourists and families from the scene. A row of ambulances was parked on Cromwell Road. A woman with a blood-soaked bandage on one foot was pushed in a wheelchair to an intersection.
Large crowds of tourists, including student groups, their plans for museum visits interrupted, milled around on the sidewalk, trying to find out what had happened. As a helicopter hovered overhead, a voice was heard shouting: “All the museums are closed. Please clear the area.”
Families leaving the packed museum said that no announcements about the incident had been made inside. They said they learned that the museums and the nearest subway station had been closed off only after leaving the building.
The London area has been hit with five attacks in the past six months. The last one was an assault with an explosive device on a train at the Parsons Green subway station that injured at least 30.
In March, five people were killed and at least 40 more injured when a knife-wielding assailant in a sport utility vehicle ran over pedestrians on Westminster Bridge. He then got out and stabbed a police officer outside the Parliament building.
On June 3, three men carrying knives and wearing fake suicide bomb vests rammed their van into pedestrians on London Bridge and stabbed several people in the nearby Borough Market, killing eight. Two weeks later, a van driver plowed into a crowd of Muslims as they finished prayers at the Finsbury Park Mosque in north London, leaving one dead.
In addition, a suicide bomber killed 22 people and wounded 59 others when he blew himself up near one of the exits of the Manchester Arena at the end of a concert in May by the American pop singer Ariana Grande.