Alan Johnston BBC, South Asia Desk

The Ministry, in a statement on its website, vowed to take action to stop what it called this "journalistic treachery".

As Alan Johnston of our South Asia desk reports, the statement has been condemned in the strongest terms by media freedom activists.

The Defence Ministry's message to the media stresses that Sri Lanka is at war. Its forces are engaged, it says, in the noble cause of liberating the country from the clutches of terrorism.

The statement says that those who undermine public support for that mission by making false allegations give aid to the terrorists.

According to the Ministry, only military officers are qualified to analyse military matters, and it attacks what it calls doomsayers and reporters who write inane comments.

It says that "traitors" in the press will be exposed.

Dire climate

The Paris-based watchdog, Reporters Without Borders has described the statement as very threatening, and part of a policy of intimidation.

It says that it opens the way to further restrictions and pressure on defence correspondents in particular, in what is already a dire climate for media freedom.

One leading commentator on military matters was recently abducted and beaten in unexplained circumstances. Another has ceased writing his weekly column. All this comes against a background of almost daily, fierce clashes between the army and the Tamil Tigers.

The military has pledged to defeat the rebels by the end of the year. It's under pressure and clearly extremely sensitive to any criticism of the way that the war is being conducted.