A bison has seriously injured a tourist in Yellowstone National Park for the second time in three weeks.

The animal tossed the 62-year-old Australian several times into the air. The unidentified man was flown by helicopter to a hospital. He had serious but not life-threatening injuries.

The man was not the only person to blame for the encounter, park officials said. Several people crowded the bison as it lay on the grass near pavement not far from the famous Old Faithful Geyser.

Yellowstone spokeswoman Amy Bartlett said: "The bison was already getting agitated."

The man stepped forward and snapped photos with an electronic notepad just five feet away from the animal, she said.

When the bison charged, the tourist had little chance to escape. Bison can weigh as much as a small car and run three times faster than a person.

Park officials recommend getting no closer to a bison than 25 yards.

It was the second bison attack in Yellowstone since summer tourist season began a month ago.

A bison in the Old Faithful area gored a 16-year-old girl from Taiwan as she posed for a picture near the animal on May 16.