The U.S. says it's very concerned that four reporters and a magazine chief executive in Burma have been sentenced to 10 years of hard labor.

The sentence is for reporting about an alleged weapons factory.

The State Department says the sentence sends the "wrong message" about Burma's commitment to freedom of expression. A spokesman is urging Burma to respect the rights of all journalists.

The now-defunct Unity journal printed a story in January saying the military had seized farmland for the factory in central Burma and that it would produce chemical weapons. The journal printed a denial by authorities.

Rights groups have condemned Thursday's sentencing. They say intimidation and arrests of journalists appear to be worsening in the former pariah state, even as official censorship has been lifted.