by David Nitkin and Brent Jones

The skies above Maryland's Camp David and the surrounding area were busy during President Bush's visit over the weekend.

There were about a dozen encroachments into off-limits airspace while the president was speaking yesterday at a ceremony for firefighters who died in the line of duty in 2006, according to the Federal Aviation Administration. All of the vioaltions appeared to be inadvertent.

All the planes drifted within 30 miles of where the president was speaking in Emmitsburg, Md., a no-fly zone that also included Camp David, the presidential retreat nestled near the cool top of the Catoctin Mountains. Four of the planes were escorted out of the area by F-16s.

The planes were headed to a benefit for the Experimental Aircraft Association and the Hagerstown Aviation Museum and apparently were unaware of the restriction, in part because they are antiques and carried no radios. Baker said the violations appeared to be unintentional.

The FAA is considering disciplinary action against the pilots, officials said. All the pilots are expected to be interviewed and could face license suspensions, said Holly Baker, a spokeswoman for the FAA.

In at least one instance, a plane was escorted to Westminster Airport in Carroll County, according to WTOP radio. The Associated Press and CBS News also reported on the violations

Bush stayed at the ceremony for fallen firefighters for more than an hour, presenting a rose, a medallion, a flag -- and embraces -- to family members of the fallen firefighters.

The president last attended the ceremony in 2001, hours before ordering military strikes in Afghanistan following the 9/11 terrorist attacks.

The president planned to return from Camp David, which is about an hour's drive north of Washington and closer via the Marine One helicopter, this afternoon.

David Nitkin and Brent Jones report for the Baltimore Sun, a Tribune Co. newspaper.