Kapow! Police dressed as Batman, Robin arrest 2 in gambling sting.

There was no bat signal, and London is no Gotham, but Batman and Robin still showed up on Westminster Bridge speeding through a throng of startled onlookers in the name of justice.

The Batman and Robin running along the bridge on Feb. 15 were two police officers in an undercover sting to curb illegal gambling at the popular tourist attraction, the Metropolitan Police said in a statement Friday.

Westminster Bridge has become a hotbed of illegal gambling, police explained, with gangs targeting tourists snapping photos along the bridge across the Thames, which gives way to stunning views of the famed Big Ben and Palace of Westminster.

The gangs target tourists by engaging them in games such as the “three cups challenge” or “shell game” police said. These often-rigged tricks involve tourists guessing under which of three cups the gamemaster is rapidly moving a ball.

But while police work the area and are well acquainted with repeat offenders, the reverse also holds true: The gangs know and can recognize the officers, packing up and leaving before they can be caught in the act.

“I knew that if we were going to catch them we would have [to] think outside the box,” Inspector Darren Watson said in the statement.

Then Watson remembered the Batman and Robin costumes he had on hand. He donned the Batman outfit, while his counterpart, police constable Abdi Osman, put on the Robin costume.

A variety of wildly dressed characters tend to frequent Westminster Bridge — charging tourists to pose for photos with them, much like in New York’s Times Square. Their idea was to blend in with the crowd. But in the video released by police, Batman and Robin are the only characters visible, dashing through the crush, with Watson grappling with one of the suspects.

In disguise, Watson and Osman arrested Eugen Stocia, 32, and Constica-Gherorghe Barbu, 53, on suspicion of providing the facilities to gamble. Barbu was convicted two days later and fined about $1,200. Stocia was convicted in absence on Thursday after failing to appear in court, and a warrant is out for his arrest. Neither Stocia nor Barbu was able to be reached for comment Saturday.

“Although dressing up may not be the most conventional policing method, we were thrilled to see that in this case it worked perfectly and the team were able to get some great results, taking these people off the street and protecting tourists and Londoners from being fleeced,” Watson said in the statement.

Watson and the Met Police did not immediately respond to a request for comment on Saturday. But in a video posted on X, the Met Police said crime on the bridge was an ongoing target: “We will continue to target those involved, arrest them and continue to put them before the courts.”