Marine Corps Base Hawaii is investigating a shocking video of a smiling Marine throwing a puppy off the top of a steep hillside in Iraq into a gully below.

The video today gained widespread attention and condemnation on the Internet.

"The video is shocking and deplorable and is contrary to the high standards we expect of every Marine," the Kane'ohe Bay base said in a release.

Base officials said the video came to their attention this morning. An investigation has been initiated. Maj. Chris Perrine, a Marine spokesman here, said "it's looking like" the Marine is based out of Hawai'i.

"We do not tolerate this type of behavior and will take appropriate action," the base said.

Two Marines are seen in combat gear smiling as one holds a white-and-black puppy by the scruff of its neck. The dog seems to be about 8 weeks old and is motionless as it is held.

"Cute little puppy, huh?" says one Marine as he smiles broadly.

"Oh so cute, so cute, little puppy," says another in a child-like voice.

The Marine holding the puppy is then seen throwing the animal overhand into a desert-like gully below. The animal yelps until it thuds to the ground at the bottom of the gully.

"That's mean," one Marine says afterward.

The 2nd Battalion, 3rd Marine Regiment of about 1,000 Hawai'i Marines recently replaced a sister unit in Iraq, the 3rd Battalion, 3rd Marine Regiment.

Marine Corps Base Hawai'i said the vast majority of Marines "conduct their duties in an honorable manner that brings great credit upon the Marine Corps and the United States."

There have been numerous stories of Marines adopting pets and bringing them home from Iraq or helping to arrange life-saving medical care for Iraqi children. Those are the stories that exemplify what we stand for and how most Marines behave."

The video was posted on YouTube. Caution, graphic content.