Thousands of fans of the Penguins and other professional sports teams might not get what they pay for in jerseys that have hit the local market, the U.S. Postal Inspection Service officials said yesterday.

About 1,000 bootleg jerseys, shipped illegally from China, were seized this week by a task force of postal inspectors, U.S. Immigration and Customs Enforcement and Pennsylvania State Police.

The shipments and sales are a rip-off for consumers and an infringement of the National Hockey League's right to market the merchandise.

Over the past week, 78 separate parcels containing about 1,000 jerseys were intercepted by the agents.

In a one-month period, agents have seized $250,000 worth of bootleg Penguins jerseys, said Andrew Richards, spokesman for the Postal Inspection Service.

"We believe there's a lot more out there that we're not aware of," Mr. Richards said yesterday.

He said the counterfeit merchandise commonly makes its way into the market year-round. The influx increases, as it has in Pittsburgh, when teams make the playoffs.

"The influx is tenfold when sports teams do this," Mr. Richards said.

Consumers are warned because the knockoffs have become more difficult to discover.

Recent seizures have uncovered jerseys that include details like team and league holograms that are sewn into the garments.

"We want consumers to be aware that they're knockoffs," Mr. Richards said. "They don't last like a genuine article."