A mini school bus with a four-year-old boy on board overturned after it was struck from behind by a semi-trailer truck at about noon today in Pembroke, Genesee County Sheriff's officials said.

The school bus, with just the driver and the one boy on board, was eastbound on Route 5 and was making a left hand turn into a drive way near Wortendyke Road when it was hit from behind. Police said the bus driver had his turn signal on.

"The bus spun 180 degrees, went into the road and across the westbound lane and overturned," said Gordon Dibble, chief deputy of road patrol. The bus ended up just off the north shoulder.

The child complained of head pain and was taken to United Memorial Medical Center in Batavia "to be checked out" but he was treated and released, Dibble said.

Neither the school bus driver nor the truck driver was hurt.

Deputies issued tickets to the truck driver, James H. Persons, 66, of Mill Village, Pa., for following too closely and other violations, including having an overweight truck.

The bus driver, Thomas Swimline, 55, Corfu was not cited in the incident.

Route 5 was closed in the area for roughly an hour after the accident.