The day after police in Fairfax County, Virginia, warned of “suspicious buses” seen trying to pick up children, officials now say there may be a valid explanation.

A Fairfax County police spokesman told WTOP that authorities are still investigating but that they  now think there was a plausible reason for a small white bus with a blue stripe to be in the area of Southington Lane in Reston early Thursday morning.

That was the first of two suspicious bus incidents that the police department reported Thursday.

The second incident involved an unmarked yellow school bus with black stripes, in the area of Chynoweth Street and Telegraph Road in Lorton.

Fairfax County police said  in a tweet Thursday night that they had identified the driver of the bus in Lorton and that did not suspect any criminal activity took place in that case, either.

The two locations where the buses were reported are in opposite ends of the county, some 27 miles apart.

Curry said there will be additional police presence when school resumes on Monday as a precaution.

A letter to families and staff members sent out by the school system Thursday reminded parents and students Fairfax County school buses will always be properly marked. “FCPS will never send an unmarked bus to pick up students,” the letter stated.

Police had asked anyone who lives near the bus stops to review footage from their home surveillance cameras and share anything they see of concern with detectives.

Anyone with information is asked to call police at 703-691-2131. Tips can also be submitted anonymously through Crime Solvers by phone at 866-411-TIPS (866-411-8477).

WTOP’s Scott Gelman contributed to this report.