WASHINGTON (Reuters) - The US government has served subpoenas on wealthy individuals in recent days in the New York area, targeting those who may have evaded taxes using offshore accounts at Swiss bank UBS AG, lawyers said.

The lawyers believe the subpoenas are based on between 250 and 280 account names the government received earlier this year when UBS paid $780 million to settle a criminal prosecution.

David Gannaway, a tax attorney at Marks Paneth in New York, has a client who has received a subpoena and knows of others.

Two other attorneys also said they had clients who had received subpoenas.

A spokesman for the US Department of Justice declined to comment.

US tax authorities say a clampdown on wealthy tax cheats is a top priority. The Internal Revenue Service recently opened a new unit to police high net-worth individuals.

"I think they always have known that (tax evasion among the wealthy) is rampant. They didn't know that it is this extreme," said Gannaway.

By one estimate, the US loses $100 billion a year to individual and corporate tax evaders.