Denver, CO (LifeNews.com) -- A Colorado pro-life group says abortion advocates stole a pro-life banner off of a truck the group rents and uses to present its message around town. During the annual Colorado Right To Life banquet on Saturday evening, the group alleges that Planned Parenthood supporters stole the mobile billboard sign.

The stolen sign reads "Planned Parenthood Kills Babies" and features a quote from Planned Parenthood founder Margaret Sanger.

Sanger is quoted saying, "we don't want the word to get out that we want to exterminate the Negro population."

"It is clear to me that those who support Planned Parenthood will stop at nothing to cover up the truth about their organization," Leslie Hanks, the vice president of the group, told LifeNews.com in a statement.

"This act of thievery only strengthens the resolve of Colorado Right to Life to expose Planned Parenthood, and work to stop them from killing babies," Leslie continued. "With the help of pro-lifers across the nation we will replace this Billboard, and we will not go away."

LifeNews.com did not receive any response from local Planned Parenthood officials about the theft.

The group was slated to use the truck and sign in a protest on Wednesday of Weitz Construction Company, which is under contract to build a new abortion center for Planned Parenthood in northeast Denver.

As LifeNews.com has reported, Denver may become the next battleground over the building of a new abortion facility in secret. Pro-life advocates in this mountain city are upset that Planned Parenthood is placing a new abortion business in the heart of an African-American community and that its beginnings are shrouded in secrecy.

Planned Parenthood expects to break ground on the new abortion center in November.

Planned Parenthood of the Rocky Mountains does about 8,800 abortions annually on women from Colorado and four surrounding states, including Wyoming.