The Braddock Road Metrorail station in Alexandria was closed for the first part of this morning's rush-hour commute because of a delay in investigating suspicious items that were spotted by a Metro employee about 3 a.m., authorities said.

Alexandria police said a Metro employee saw the items -- two suitcases and a backpack -- near the station's bus waiting area about 3:10 a.m.

The luggage remained undisturbed for at least two hours after being discovered because Metro transit police's bomb squad did not get to the scene until 5:05 a.m., Alexandria police Lt. James Bartlett said.

Alexandria police do not have their own bomb squad. If the packages had been spotted on a city street, rather than a Metro station, Bartlett said, the police department would have sought help from neighboring Arlington or the state or military police.

"We don't have a hazardous materials unit, so we don't mess with it," Bartlett said.

Metro spokeswoman Cathy Asato could not explain the delay in getting the bomb squad to the station, but said "it is something that we will look into."

The station was closed for the night when the luggage was discovered. It normally would have reopened at 5 a.m.

As of 7 a.m., Metro's bomb squad had examined the packages. They were deemed harmless, and the station -- which serves both the Yellow and Blue lines -- reopened shortly after 7:30 a.m.

"Abandoned property, apparently," Bartlett said with a sigh. "I wish people knew what kind of work this causes for people. We have to treat packages like that as suspicious until we know better."

In downtown Washington, meanwhile, the rear wheels of a Metrobus caught fire near Farragut Square about 5:45 a.m. Asato said the driver of the Chevy Chase-bound L2 bus "heard some kind of popping sound," pulled the vehicle over and told the three passengers on board to disembark.

The blaze was quickly extinguished, and Asato said the cause was under investigation.

"It wasn't inside the bus, and nobody was injured," she said. "That's the good news."

The early morning incidents came less than a day after smoke on the rails at the Farragut North station{vbar} caused delays during the morning rush hour, and hours before the Farragut North station was shut down because of a fire reported just after 10 a.m.

Metro officials said passengers also reported possible fires on the Orange and Blue lines, at the Smithsonian station and at West Falls Church. Neither report proved true, although each triggered some delays as they were checked out.

Metro spokeswoman Lisa Farbstein said passengers may have grown more vigilant after hearing about the fires at Farragut North. "People are being very conscious of what they are seeing, and that's a good thing," she said, adding that anybody who sees something suspicious should report it.