TV comic Ricky Gervais was water-bombed by a group of students as he jogged outside the University College campus in London.

But the joke turned sour when Gervais marched into the building and gave the pranksters a telling off.

One student defended the prank saying, "It was really hot and some people were making water-balloons. They shouted at him, but they ignored him, so they chucked a water balloon at him to get his attention.

"They thought he'd see the joke, but he marched up to the door and rang the bell."

But the Office funnyman said, "I went to check it wasn't some old woman emptying her chamber-pot, but all I found were some spotty students. I gave them a ticking off as a joke, but they looked terrified, so I felt guilty afterwards."