"So as a precaution, it's muzzling the press before it embarks on measures that it knows will be unpopular."
Deby, a former fighter pilot re-elected in May at polls boycotted by the opposition, is using powers granted by the state of emergency last month, aimed at curbing the spread of ethnic violence from Sudan's Darfur region into eastern Chad.
Advanced copies of newspapers must now be submitted before publication and are cut by the censor. Radio stations must also provide their pre-recorded material for censorship and they can be fined for live broadcasts which stray from guidelines.
Nadjikimo Benoudjita, the editor of Notre Temps newspaper and president of the Chadian Association of Editors for the Private Press, said: "We can understand being forbidden to discuss inter-ethnic conflict - that is the reason given by the government for the censorship.
"But now we can't discuss Darfur or the conflict between rebels and government forces, or even some political topics. We are not even allowed to say that we are censured."
Hundreds of Chadian villagers have been killed in recent weeks in fighting between Arab and non-Arab communities, mirroring the violence across the border in Darfur. Rebels have mounted a series of attacks to seize control of towns in eastern and central Chad.
Hourmadji Moussa Doumgor, Chad's communications minister and the government's spokesman, expressed surprise at the media strike during what the government has dubbed a "state of war".
Doumgor, himself a former journalist, said: "During war-time, if there are discordant voices which sow doubt into the minds of citizens, they are playing the enemy's game."