White House On Alert After Nearby Fire, Suspicious Vehicle

The U.S. Secret Service said authorities responded to a fire and were searching a vehicle near the White House Saturday morning.

Secret Service spokesman Brian Leary says a vendor cart caught fire around 10 a.m. Saturday at 15th and G streets. He says firefighters responded and contained the blaze.

According to a White House pool report, a loud noise was heard on the White House South Lawn before President Obama and the first family were expected to depart in a helicopter. The first family was not yet on the lawn when the noise was heard.

Around the same time, Leary says a bomb-sniffing dog detected something on a vehicle at 16th Street and Constitution Avenue. That vehicle is being checked out by the Secret Service and other law enforcement officials.

There is no indication that the two incidents are related.

© 2015 CBS Interactive Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.