Republican campaigners in Missouri are beefing up security after a laptop containing "strategic information" was stolen from a campaign field office of presidential contender John McCain.

The theft occurred at a campaign office in Independence, Missouri, sometime between 10 p.m. Tuesday and 6 a.m. Wednesday, according to Tina Hervey, a spokeswoman with the Missouri Republican Party. When staffers showed up for work Wednesday, they found that someone had thrown a brick through the glass windows fronting the office, rifled through a bag and stolen a Dell laptop belonging to a regional campaigner.

The laptop contained "strategic information for the [Republican party] on how we are going to reach out to people in the Kansas City area," Hervey said.

The office, known as the Kansas City Victory Office, supports the campaign efforts of McCain and local Republican candidates.

Staffers worry that the theft may have been politically motivated. They say the laptop contained information that would be valuable to a political opponent and that it appeared to have been singled out. Twenty-two Asustek Computer Eee PCs, which are used by phone-bank volunteers and do not contain sensitive information, were left behind by the thieves, Hervey said.

Local police are investigating but have not identified a suspect, she said.