Four men were released on bail and were ordered to return to a police station Monday, when they may be charged with assault, a police spokesman said.
The 42-year-old actor was outside a movie theater in central London's Leicester Square doing press interviews Sunday when a man squirted Cruise with a water pistol disguised as a microphone, London's Metropolitan Police said.
Cruise appeared to laugh at the incident but then asked the prankster: "Why would you do that?"
As the man gave a barely audible excuse, Cruise said: "Do you like thinking less of people, is that it?" The prankster tried to walk away but Cruise reached across the metal barrier, held his arm and said: "Don't run away. That's incredibly rude. I'm here giving you an interview and you do that ... it's incredibly rude."
The actor grew increasingly irritated and told the man: "You're a jerk."
Police detained the man who squirted Cruise and arrested three other men who filmed the incident. The four were working on a new comedy show for British TV station Channel 4 in which celebrities are the targets of practical jokes. They were released on bail several hours later.
Katie Holmes (search), who became engaged to Cruise last week, was at the premiere but not by Cruise's side when the incident occurred.
In an interview with Newsweek magazine, on newsstands Monday, Spielberg denies that media attention on Cruise and Holmes forced a change in the publicity campaign for "War of the Worlds." The couple went public with their romance in April.
"People say, 'Oh, you didn't put Tom on the poster because of what happened. No. The poster was designed in January ... and my decision with all my films has been to use iconography on the posters," Spielberg says. "Tom was fine with that. It's the first time Tom has not been on a poster in his career, by the way."
As for Cruise's exuberant appearance on "The Oprah Winfrey Show" last month, Spielberg tells the magazine: "What Tom did on 'Oprah' was exactly what Tom did with me when he first told me about Katie Holmes. But the press didn't like the way Tom bared his soul to Oprah."