WASHINGTON, April 25 (Reuters) - An unusual new flu virus has spread widely and cannot be contained, the U.S. Centers for Disease Control and Prevention confirmed on Saturday.

"It is clear that this is widespread. And that is why we have let you know that we cannot contain the spread of this virus," the CDC's Dr. Anne Schuchat told reporters on a conference call.

The strain of swine flu is suspected of killing as many as 68 people in Mexico and infecting more than 1,000 more, including eight in the United States. (Reporting by Maggie Fox, editing by Patricia Zengerle)