More than 14,700 U.S. taxpayers came forward to disclose billions in offshore bank accounts in 70 countries under a voluntary Internal Revenue Service program allowing most to avoid criminal prosecution as long as they pay what they owe, IRS officials said Tuesday.

A flood of people came forward in the last days before the amnesty program expired Oct. 15, IRS Commissioner Doug Shulman said. The final total far surpasses the number who disclose offshore accounts in a typical year — about 100 — and comes amid a broad U.S. crackdown on international tax evasion at Swiss bank UBS AG and other institutions.