BOULDER, Colorado -- Even the most powerful man in the world cannot avoid the occasional food spill.

President Barack Obama was meeting and greeting outside popular local restaurant The Sink, in Boulder, Colorado, on Tuesday night when a girl spilled yogurt on him, CBS News' White House correspondent Mark Knoller reported.

"Ooops. A girl spilled yogurt on Pres Obama as he was shaking hands along a ropeline outside The Sink. She apologized," Knoller wrote on Twitter.

"Getting yogurt on the president -- you've got a story to tell," Obama told the girl, who replied, "I'm very embarrassed," according to Knoller.

In a photo posted on picture-sharing site Instagram, another woman at the event -- user "madloid55" -- showed herself posing with Obama. The accompanying caption read "Just met Obama at the Sink."

It was not known if the photo was taken before or after the yogurt spill. There were no telltale signs of the dairy product on the president's shirt or pants in the picture.

Obama stopped by the eatery on his way to the University of Colorado in Boulder, where he was giving a speech as part of a three-state swing to push for action on interest rate increases.

Update -- Obama did talk about the yogurt incident in his speech: