Image caption A photo editor said photographers were "in shock"

The entire photography staff at a historic Chicago tabloid newspaper and its suburban subsidiaries has been laid off, the photographers have said.

The Chicago Sun-Times will instead rely on reporters to shoot photos and video, with freelancers also filling in.

The job cuts come as newspapers across the world struggle with declining advertising and subscription revenues.

The photographers' union vowed to fight the job cuts, which affect as many as 30 people.

Steve Buyansky, a photo editor for three of the smaller suburban subsidiary publications, said the photographers were "in shock".

In a statement, the newspaper said: "The Chicago Sun-Times continues to evolve with our digitally savvy customers, and as a result, we have had to restructure the way we manage multimedia, including photography, across the network.

"The Sun-Times business is changing rapidly and our audiences are consistently seeking more video content with their news.

"We have made great progress in meeting this demand and are focused on bolstering our reporting capabilities with video and other multimedia elements."

The Chicago newspaper is the eighth-largest daily paper in the US, according to industry tracker Alliance for Audited Media.

The media group went into bankruptcy under the direction of press baron Conrad Black. The paper and its 40 subsidiaries were purchased in 2011 by Michael Ferro, a wealthy Chicagoan.