Family of black bears chase tourists on bridge at Yellowstone National Park

LOS ANGELES -- A family of black bears are seen chasing tourists in a video captured at Yellowstone National Park.

The wild animals had some people running for safety, while others calmly snapped photos.

The mother black bear and her three cubs unexpectedly appeared on a bridge, which was lined with sightseers earlier this week. The mother appears equally terrified and ends up charging at one family as they scramble to their car.

There was even a group of photographers clicking away as one of the young bears explores the bridge. Sightseers and the family of bears parted ways without any attacks or aggression, but officials said the run-in is an example of the dangers in the national park, especially when there are 3.5 million visitors each year.

"A mother bear with cubs is not something you want to try and get too near to at all," said Jack Hanna, director emeritus of the Columbus Zoo.

Spring may be the park's peak tourist season, but the warmer weather is also the time when black bears are usually out in the open.

"These bears, they wake up with warmer weather. They're thirsty and hungry, and they come out. This is their time of year," Hanna said.

The best defense against a bear is to keep your distance, wildlife experts said. Yellowstone regulations require visitors to stay at least 100 yards away from bears at all times.

"It's a beautiful animal we can all enjoy. It's their home. Treat them with respect and film them at a distance, that's all," Hanna said.