Updated

The Washington Post and the Guardian have won Pulitzer Prizes in public service for revealing the massive U.S. government surveillance effort.

The awards, American journalism's highest honor, were announced Monday.

The newspapers' disclosures about the National Security Agency's spy programs show the government has collected information about millions of Americans' phone calls and emails based on its classified interpretations of laws passed after the Sept. 11 attacks.

The stories are based on thousands of documents handed over by NSA leaker Edward Snowden.

The Boston Globe has been awarded a Pulitzer Prize in breaking news, and The New York Times has won two Pulitzers in photography categories.