YANGON, Burma (AP) — Four reporters and the chief executive officer of a magazine in Burma have been sentenced to 10 years at hard labor in prison on a national security charge for investigative stories about a weapons factory.

All five men from the Yangon-based Unity journal were sentenced by a court Thursday for violating the 1923 Burma State Secrets Act pertaining to trespassing in a prohibited area with prejudicial purpose. The law was enacted when Burma was a British colony called Burma.

The weekly magazine published stories in January alleging the military had seized more than 3,000 acres (1,200 hectares) of farmland in Burma’s central Magwe Region to construct a weapons factory. It reported allegations that the factory would produce chemical weapons, also printing a denial by authorities of the latter allegation.