Secret Service spokesman Eric Zahren said there was no order from the Secret Service to stop screening people going to the Obama rally Wednesday at Dallas's Reunion Arena. He said that the event's security plans didn't involve having each participant pass through a magnetometer, as may be the case at other events.

The Fort Worth (Texas) Star-Telegram reported that some police at the event expressed concern about people not passing through metal detectors.

"Any allegations to the fact that we had suspended screening or deviated from the original security plan would be entirely inaccurate," Zahren said.

Obama, D-Ill., spoke before some 17,000 supporters at the rally ahead of the March 4 primary election in Texas. There were no security-related incidents.

While stressing that security preparations are different for each venue and event, Zahren said officials were happy with the security plan for the rally at Reunion Arena and the way it was implemented.

"This in no way constituted a security lapse at this venue," Zahren said, adding that the security measures were developed with Dallas-area law enforcement personnel to "come up with a robust and comprehensive layered security plan that didn't rely solely on any specific countermeasure to secure the area."