BEIJING, April 22 (Xinhuanet) -- The U.S. Food and Drug Administration Monday warned Pfizer Inc. for not mentioning the risks of Viagra in an online advertisement.

    The advertisement is a 30-second video that featured a group of men in a Nashville studio playing instruments and singing a song called "Viva Viagra" praising Viagra. 

    The U.S. regulator said in a warning letter that Pfizer's erectile dysfunction drug violated the agency's advertising rules and did not disclose "any risk information associated with Viagra." It called on the company to discontinue the advertisement.

    "The video raises public health and safety concerns through its complete omission of risk information for Viagra by suggesting that Viagra is safer than has been demonstrated," the letter said.

    In a statement Pfizer said a technical issue prevented the risk information from displaying on a banner accompanying the video and that it has since pulled the ad.

    "We regret that the Internet video ran without the appropriate safety information," the company said.

    (Agencies)