The rally, led by Veterans for Peace, trouped from the state Capitol to the Xcel Center several blocks away behind a flag-draped coffin, the Star Tribune reported. As they neared a security fence, organizers announced that those who wanted to perform an act of civil disobedience could turn left, the Minneapolis newspaper said.
At that point, nine people, including retired surgeon David Harris of Red Wing, crawled under a security tape and made contact with a piece of security fencing. Riot gear-clad Ramsey County sheriff's deputies moved in and took the nine into custody, the Star Tribune said. Seven were booked and two were released.
Earlier in the day, St. Paul Mayor Chris Coleman defended raids and arrests carried out ahead of the convention.
"We are making sure that people here to legitimately protest have the right to do that, but people engaging in criminal activity are not going to be able to do that," Coleman said.
Police have picked up, and then released dozens of people, though at least five were jailed in pre-convention actions.
The convention starts Monday but party activities will be severely curtailed because of Hurricane Gustav.