Image copyright AP Image caption The Washington Post's Barton Gellman wrote some of the NSA surveillance stories that won the prize

The Guardian and Washington Post have shared the Pulitzer Prize for public service journalism for a series of stories on US electronic spying.

Their reporting was based on documents leaked by former National Security Agency contractor Edward Snowden.

Among other winners of the top prize in US journalism was the Boston Globe, for breaking news reporting.

Two staff writers of the Reuters news agency were awarded the prize for international reporting.

The Pulitzer Prizes are awarded by the Columbia University journalism school.

'Authoritative and insightful'

In giving the top prize to The Guardian US and the Washington Post, the Pulitzer committee said the Guardian helped "through aggressive reporting to spark a debate about the relationship between the government and the public over issues of security and privacy".

It said the Post's stories were "marked by authoritative and insightful reports that helped the public understand how the disclosures fit into the larger framework of naional security".

Mr Snowden, in a statement published by The Guardian, called the award "a vindication for everyone who believes that the public has a role in government.

"We owe it to the efforts of the brave reporters and their colleagues who kept working in the face of extraordinary intimidation," added Mr Snowden, who has been charged with espionage in the US and is currently a fugitive in Russia.

Meanwhile, the Boston Globe provided "exhaustive and empathetic coverage of the Boston Marathon bombings and the ensuing manhunt that enveloped the city", the committee wrote of the paper's coverage of the 15 April 2013 attack.

Chris Hamby of the Center for Public Integrity was awarded a Pulitzer for his reporting on how lawyers and doctors conspired to deny benefits to coal miners stricken with black lung disease.

Times wins two

Image copyright Reuters Image caption NSA leaker Edward Snowden provided a cache of documents to The Guardian and Washington Post on the agency's electronic spying programme

The top prize for US reporting was awarded to The Gazette in Colorado for its examination of mistreatment of wounded combat veterans, while the prize for international reporting went to Reuters for reports of persecution of a Muslim minority group in Burma, also known as Myanmar.

The editorial staff of the Oregonian in Portland won the prize for commentary for pieces explaining pension costs.

Tyler Hicks of the New York Times won for breaking news photography for images captured during a terrorist attack at Westgate Mall in Kenya. Also for the Times, Josh Haner won in the feature photography category for a "moving" essay on a Boston Marathon bomb blast victim who lost most of both legs.

Among other categories, Donna Tartt, author of The Goldfinch, was awarded the Pulitzer for fiction writing, while Don Fagin received the award for general nonfiction for his work, Tom's River: A Story of Science and Salvation.

Members of this year's selection committee included Katherine Boo, a staff writer for The New Yorker, and Eugene Robinson, a columnist for The Washington Post.