The Associated Press won the Pulitzer Prize for public service for reporting on abuse in the seafood industry that helped free 2,000 slave laborers, and Reuters and The New York Times shared the breaking news photography award for images of the European refugee crisis.

The Pulitzer Board, in conferring the most prestigious honors in US journalism and the arts on Monday, also honored the Los Angeles Times for breaking news reporting for its coverage of the massacre by Islamist militants in San Bernardino, California.

This year's announcement at New York's Columbia University marked the 100th anniversary of the Pulitzers, which began in 1917 after a bequest from newspaper publisher Joseph Pulitzer.

The AP's prize-winning "Seafood from Slaves" report was an investigation into the mistreatment of workers in Southeast Asia used to supply seafood to American supermarkets and restaurants. The coverage resulted in the freeing of 2,000 slave laborers and sweeping reforms, the board said.

The reporters "found captive slaves, countering industry claims that the problems had been solved," AP Executive Editor Kathleen Carroll wrote in her nomination letter to the Pulitzer judges.

"US customs records show the (slave-peeled) shrimp made its way into the supply chains of major US food stores and retailers such as Wal-Mart, Kroger, Whole Foods, Dollar General and Petco, along with restaurants such as Red Lobster and Olive Garden," the AP reported in the series of 10 articles.

The New York Times, with a record 117 Pulitzer prizes and citations before this year's announcement, added two more in 2016, taking the prize for international reporting in addition to its photography award.

The Boston Globe, the Tampa Bay Times and The New Yorker magazine also won two awards each. In total, the board handed out prizes in 21 categories, selected from about 3,000 entries.

In the awards for letters, drama and music, the musical Hamilton by Lin-Manuel Miranda won for best drama. The Pulitzer board called the Broadway hit "a landmark American musical about the gifted and self-destructive founding father whose story becomes both contemporary and irresistible."

Viet Thanh Nguyen won the fiction award for The Sympathizer, an immigrant story about a "man of two minds" and two countries, Vietnam and the United States.

The board awarded the history prize to the T.J. Stiles book, Custer's Trials: A Life on the Frontier of a New America.

The Reuters photo coverage of Middle Eastern migrants arriving in Europe was led from Greece by Yannis Behrakis, chief photographer for Greece and Cyprus.

The Tampa Bay Times and the Sarasota Herald-Tribune shared the 2016 prize for investigative reporting. The two Florida newspapers won for collaborative reporting on violence and neglect in the state's mental hospitals.