U.K.-based Angry Robot Books is closing down its young adult and crime/mystery imprints, effectively immediately.

The company, which has U.S. distribution, blamed the closures on "market saturation.” With the move, Angry Robot will shut down its Strange Chemistry YA imprint as well as its Exhibit A mystery imprint, and will not release any new titles.

In a post on its website, Angry Robot said its core Angry Robot science fiction line is “robust” and that it has plans to increase its output from two titles a month to three.

Angry Robot Books was started in the U.K. in 2009 by Marc Gascoigne as part of HarperCollins UK, but became an indie house in 2010 when it received backing from Osprey Publishing. The closing of the imprints is being seen as part of a strategic review by Osprey of its properties, a review which may include a sale of the company or parts of the company. Angry Robot started its YA line in 2012.