Harry Potter star Emma Watson was left "quite shaken" after students from Harvard University stalked her during a recent football match.

The actress, who attends Brown University, Rhode Island, was at a game between the two schools last weekend, but security guards had to surround her to protect her from harassment, reports said.

Harvard's student magazine The Voice targeted Watson and posted a blog on its website stating supporters would try to draw as much attention to her as possible.

The post read: "We will be Live-Tweetin' the game and possibly stalking Emma Watson, so keep your eyes peeled for that, too!"

During the match, students from the Harvard Voice wrote a series of posts on Twitter.com, including: "In enemy territory. Lookin for a certain witch," and, "Watson found. I repeat Watson found."

The magazine also posted a photo of the star and branded the stalking campaign a "success".

But after a series of complaints, the editor of The Voice attached a note to the picture saying: "There seems to be much ado about nothing over this photo and liveblog. Understand that these live tweets were made to be intentionally outrageous and overblown."