As McCain began a speech to about 1,000 supporters in Davenport, he was interrupted by a young woman who hoisted herself onto a colleague's shoulders and unfurled a sign reading "War Is Over" and yelling "We want peace," The Washington Post reported.

The woman was quickly shouted down and she and her companion were escorted out, the Post said. McCain used the incident as example of "some people that just don't get it."

"People are trying to stay in their homes, keep their jobs," McCain said. "Is what they want for us to yell at each other? No. They want us to sit down, Republican and Democrat, and work together."

McCain's Saturday stop at Davenport's RiverCenter represented his third Iowa trip in almost as many weeks, coming after McCain campaign officials said they were doubling the size of his operation in the state.

Polls show his Democratic opponent, Sen. Barack Obama of Illinois, leading by double digits in Iowa, the Des Moines Register said. But McCain aides say he is still competitive there because of a large number of undecided voters.