Best-selling US author Tom Clancy, known to millions for his Jack Ryan series of novels, has died aged 66, his publisher has confirmed.
Clancy wrote a string of best-selling spy and military thrillers.
Several of his books featuring CIA analyst Ryan were adapted into successful films, including The Hunt for Red October and Patriot Games.
The former insurance broker died in a Baltimore hospital near his Maryland home, according to reports.
The Hunt for Red October (1984) was Clancy's first published novel and sold more than five million copies.
President Ronald Reagan helped to fuel the success of the book when he called it a "perfect yarn".
The novel was made into a successful film in 1990, starring Alec Baldwin as Ryan and Sir Sean Connery as Soviet submarine captain Marko Ramius.
Harrison Ford went on to play Ryan in film versions of Patriot Games and Clear and Present Danger, while Ben Affleck played him in 2002 release The Sum of All Fears.
Jack Ryan: Shadow One, a new film to feature the character directed by Sir Kenneth Branagh, is set for release this December.
As well as a successful writer, Clancy also became closely associated with the world of video gaming.
In the 1990s he founded Red Storm Entertainment, later bought by Ubisoft, which developed games based on Clancy's ideas.
Blockbuster video game titles bearing his name included Splinter Cell, Ghost Recon and Rainbow Six.
