(Stephen Flood, The Express-Times/AP Photo)

ABC News' Emily Friedman reports:

UPDATED QUAKERTOWN, Pa. - The Romney bus tour hit a speed bump today when more than a hundred protesters showed up at a gas station where the presumptive GOP presidential candidate was scheduled to make a stop, and the candidate's motorcade quickly rerouted to another location just three miles away.

Romney himself acknowledged the change in venue - his fourth scheduled stop on a five-day, six-state bus tour - while shaking hands with voters inside a WaWa gas station.

"I was asked, I think you asked me, why we're at this Wawa, instead of the other WaWa? I understand I had a surrogate over there already, so we decided to pick a different place," said Romney, who when initially asked about the change had joked that he had moved "just to get a good sandwich."

"My surrogate is former Gov. Rendell, who said we could win Pennsylvania," Romney said. "I'm happy to hear that, so we're happy to be here and see some folks here."

Despite Romney's characterization of Ed Rendell, the former Democratic Pennsylvania governor is campaigning for President Obama in Pennsylvania. Romney was referring to an interview with Bloomberg News' "Bloomberg View" that Rendell gave in which he the president would not win major sections of the battleground state.

According to local reports, Rendell, along with 150 to 200 anti-Romney protesters, had shown up at the original gas station to tout Obama's message, speaking ahead of when Romney was scheduled to arrive.

But a Romney campaign official said they were prepared for the disruption and that the re-routing was not a spur-of-the-moment decision.

"We knew yesterday," the aide said referring to the protesters' plans. "We knew what they were going to pull."

The official noted that advance staff began scouting out alternative locations in advance and picked the other nearby Wawa market and gas station. But the campaign kept the new plans a secret until the last minute in order to trick the protesters into thinking Romney would still visit the original event site on Saturday afternoon.

"We didn't let them have their moment of glory," the aide said in an interview with ABC News.

About 50 people greeted Romney at the new location, including a little league baseball team, and the candidate appeared surprised that they had figured out where to find him, remarking, "I wondered how you knew we'd be here."

Romney spent no more than about 12 minutes at the gas station, quickly re-boarding his campaign bus to head to Cornwall.

ABC News' Michael Falcone contributed reporting.