ST. LOUIS • A bullet hit the rear of a school bus Friday afternoon in St. Louis, scaring the driver and about 20 students inside but injuring no one, authorities say.

The shot hit the school bus as it was dropping off students at West Florissant Avenue and Hiller Place about 4:25 p.m. Police said no one was hit.

The bus was dropping off students from the Imagine Academy of Environmental Science and Math, 1008 South Spring Avenue, said Debbie Jones-Fowler, a representative with the Student Transit bus company.

About 20 students were aboard when the bullet hit the bus, Jones-Fowler said.

Several youths were standing near the bus when one of them threw something at the bus, Jones-Fowler said. Then, one of them pulled out a handgun and fired one shot that hit the rear door.

She said the youths scattered and ran off after the shot was fired. The shot spooked the students and bus driver, who told the students to get down on the floor of the bus for safety, she said.

Children were later transferred to another bus to get home.

Police are investigating the incident.