A half dozen people were injured Saturday after a small tour boat hit a whale or a whale shark off a coastal city of Mexico's La Paz, authorities said.

The state civil defense office posted a video clip showing the open boat with an awning hit something in the open water. The boat careens out of the water with sufficient force to throw at least one passenger through the awning and possibly off the vessel.

The office said three children aboard the craft suffered light injuries, but two adults were hospitalized after the accident, which occurred Friday. The office said another person aboard the craft was taken by navy personnel to a clinic for treatment.

Mexican regulations require boats involved in whale watching to stay a safe distance from the creatures, but the boat involved in Friday's incident did not appear to be engaged in whale watching – or watching out for whales.

The civil defense office said the accident is under investigation. The video, and the leap the boat made after hitting the creature, suggest it was going at a high rate of speed.