Two school buses carrying sixth-graders to Yosemite National Park collided Thursday, injuring a dozen children and a parent, park officials said.

The children from Yolo Middle School in Newman were on their way to a day hike when one bus rear-ended the other about a mile from Yosemite Valley, park spokesman Scott Gediman said.

Those hurt were taken to area clinics and hospitals for minor to moderate back and neck injuries, Gediman said.

Different buses were being used to transport uninjured children back to Newman, said Rick Fauss, superintendent of Newman-Crows Landing Unified School District.

"They were 10 minutes into the park, and the whole string of cars came to a stop faster than they anticipated and the driver wasn't able to stop fast enough," Fauss said.

No other vehicles were involved in the collision, which is under investigation.