A new report says the head of a state-run firm in North Korea was executed last year for making an international call without permission from authorities.

Reporters Without Borders said in its annual report that the number of such execution cases is sharply increasing.

The international organization added that a magazine secretly designed by North Korean journalists was published for the first time last November. The magazine, entitled “Im-jin River,” seeks to relate real stories from the reclusive state in close cooperation with Japanese wire services.

The report added that North Korea strengthened jamming of outside radio broadcasts in May of last year to counter expanded coverage on the North by international media.

The group said that as a result, signals from five radio broadcasts toward North Korea, including Radio Free Asia and Voice of America, are now being jammed.