Pyongyang has sentenced four South Korean journalists to death for book reviews that insulted the North, state media said Thursday.

The Chosun Ilbo and the Dong-A Ilbo, both of them conservative newspapers, reviewed the new Korean edition of "North Korea Confidential", a book by two Seoul-based British journalists first published in 2015.

The work details the growing role of the market in daily lives in the North, where South Korean television dramas are circulated on the black market, and fashion items and hairstyles from the South are copied.

Those caught in possession of DVDs or USBs containing South Korean TV dramas can bribe their way out of any trouble, it says. 

For the Korean edition the book has been retitled "Capitalist Republic of Korea", in a play on the North's official designation as a democratic republic, and its cover replaces the red star in the North's coat of arms with a dollar sign.

By reviewing the book, newspapers "committed a hideous crime of seriously insulting the dignity of the DPRK" as part of a "sordid smear campaign", the North's Central Court said.  

The papers had the "temerity" to carry a picture of the book cover, it added in a statement carried by the official Korean Central News Agency.

"They have reached the state of slandering and insulting even the inviolable name of our country and its national emblem," it said.

One journalist from each newspaper, and the presidents of both publications were sentenced to capital punishment, it said.

"The criminals hold no right to appeal and the execution will be carried out any moment and at any place without going through any additional procedures," it added.

No penalty was specified for the books' authors, former Economist correspondent Daniel Tudor, and James Pearson, who writes for the Reuters news agency.

Tudor has not been to North Korea since publication and is understood not to have plans to go again.

It is not the first time Pyongyang has declared a death sentence on South Korean citizens.

In June it said it was imposing the death penalty on the South's former president Park Geun-Hye and her former spy agency head Lee Byung-Ho, claiming its state security authorities had foiled a plot by US and South Korean spy agencies to kill North Korean leader Kim Jong-Un.

That came after Kim's estranged half-brother Kim Jong-Nam was murdered at Kuala Lumpur international airport in February, allegedly by two women using the banned nerve agent VX in a killing widely blamed on Pyongyang.