Channel 4 appealed to Tom Cruise to see the funny side of a water-squirting prank today as a freelance TV crew who ambushed him in Leicester Square waited to hear whether the star would press charges of assault.

The crew was shooting a comedy sketch at last night's London premiere of the War of the Worlds, where Cruise and fiancee Katie Holmes, who got engaged in Paris last Friday, were greeting the crowds.

As he answered questions from journalists a bogus reporter, wearing a white and green T-shirt, stuck out a joke microphone and used it to squirt water into Cruise's face.

The actor struggled to keep his cool, turning on the man to say: "Why would you do that ... why would you do that ... why would you do that?"

As the interviewer offered a barely audible excuse, Cruise said: "Do you like thinking less of people, is that it?... You're a jerk ... jerk ... you're a jerk."

Cruise then held the man back before security guards escorted him into the Odeon cinema, where he was arrested along with the three members of his crew.

A Channel 4 spokesman said: "The incident was for a new Channel 4 entertainment show, part of which involves playing comedy pranks on celebrities and on members of the public.

"The water-squirting was not intended to cause offence and was very much in a spirit of fun. We hope Tom Cruise will be able to see the joke in the spirit with which it was intended."

He added: "The stunt was intended to be light-hearted rather than malicious and we would apologise to Mr Cruise for any offence caused."

The four men were bailed last night but are to face questioning over a possible assault charge later today. A Scotland Yard spokesman said: "We will see whether to pursue the charges, see whether the victim wants to pursue it."

It is not the first time that the crew, who are filming a new show to be called Entertainment 4, have waylaid a celebrity with their water-pistol microphone. They reportedly squirted American heiress Paris Hilton at the Cannes Film Festival.

They also squirted Sharon Osbourne in Central London earlier this month, although the reality TV star decided to get even, ducking into a nearby restaurant and grabbing a champagne bucket full of ice and water which she upended on the cameraman.

After last night's incident, an aide rushed up to the 42-year-old star to help him dry himself off with a towel. Cruise carried on with his walkabout, which ended up lasting around two hours.

A spokeswoman for the star was quoted as saying today: "Tom does want to take action but we will decide in due course what that will be. He is not just going to forget about it.

"He wants to make sure we get to the bottom of it. We want to know who was involved and what it was all for. We have not received an apology and are still waiting to get hold of the people at Channel 4 and at the production company.

"We have been told that there is no one there at present. We are doing everything we can to get some answers.

"I understand that the prank was for a new Friday night show and that they did a similar thing to Paris Hilton in Cannes and they pulled a similar kind of stunt on Sharon Osbourne a couple of weeks ago."

Asked if they would consider legal action the spokeswoman replied: "Tom does want to take action but we don't know precisely what until we know more about the people we are dealing with."