Police have expressed their concerns that Occupy Wall Street protesters could disrupt the World Series, which starts tonight in St. Louis.
The St. Louis branch of the Occupy movement said on its Facebook page it would be present at the opening game of the series at the Kiener Plaza campsite near Busch Stadium.
"Come watch the game with the 99 percent...Show the world that there isn't a need for corporate sponsors to enjoy baseball."
Police fear potential plans for a huge rally and the releasing of a streaker inside the stadium, according to a Daily Mail report.
"There are times that we know that there are certain elements that can get drawn into large protests and other people who have other agendas," a St. Louis police spokesman told CBS St Louis.
Around 25 to 100 demonstrators have camped at the plaza since the beginning of the month, according to a Reuters report. Ten people were arrested by police for curfew violations last week, but authorities and protest organizers have worked out an arrangement permitting the demonstrations to go on.
"We recognize that people have the right to protest and as long as they are peaceful we are more than happy to have them down there," said Kara Bowlin, a spokeswoman for Mayor Francis Slay.
Security will be high at the stadium as Michelle Obama and Vice President Joe Biden are expected to attend. Prior to the game, Obama and Biden will take part in a ceremony at Busch Stadium as part of Major League's Baseball "Welcome Back Veterans" program and the first lady's "Joining Forces" initiative.
MLB commissioner Bud Selig said he is "honored" to have Obama and Biden at the ceremonies.
President Obama attended a playoff game in St. Louis last week and no problems were reported.
Fans will be allowed to enter the stadium three hours before the game and have been told to expect security checkpoints on the gate of the stadium.
The Occupy Wall Street protests began on Sept. 17 have spread to locations around the world.