WASHINGTON (AP) -- IRS criminal investigators this week conducted raids in seven cities to shut down tax preparation businesses suspected of abusing a one-time telephone tax refund.

The Internal Revenue Service, in a statement yesterday, said some tax-return preparers are requesting thousands of dollars of refunds for clients despite IRS pronouncements that the tax break should be in the $30 to $60 range.

"We have seen limited but serious instances of abuse, and we've sent in criminal investigators to pursue the matter accordingly," IRS Commissioner Mark W. Everson said.

Investigators served search warrants at tax preparation businesses in Atlanta; Dallas, Tyler and Athens, Texas; Riverside, Calif.; Miami, Fla.; and Baton Rouge, La. Agents temporarily closed businesses, seizing computers and documents to be used as evidence.

The tax agency said that IRS auditors also are visiting tax preparers across the nation who are seeking questionable telephone tax refunds. The agency is advising taxpayers to stay away from preparers making exaggerated claims about refunds.