Officials will use the day off to inspect all of the district's 200 buses and confer with a task force investigating the shootings, said South-Western City Schools Superintendent Kirk Hamilton. The district serves about 20,000 students in grades kindergarten through 12.
"We are uncertain of the exact location in which these incidents have occurred," Hamilton said Wednesday night. "We are going to make every effort to ensure the safety of our students at all times."
The Franklin County sheriff's office declined comment.
Meanwhile, investigators linked a bullet fired at a house to the series of shootings along Interstate 270, which encircles the city. The house is about 2 miles north of the interstate and becomes the northernmost site connected to the case.
Chief Deputy Steve Martin said Wednesday investigators confirmed through ballistics tests that a bullet recovered from the house was fired by the same gun that killed a car passenger Nov. 25 on the highway.
The bullet was the seventh to be positively linked to the shootings, but investigators believe 16 shootings reported since last May are connected.
"In addition to increased patrols of marked and unmarked units, every investigative tool available is being utilized to prevent further incidents from occurring," said Martin. However, he said, the motive for the shootings remains unclear.