Chadian President Idriss Deby Itno on Thursday declared a nationwide state of emergency as France gave new details of the support it has given the African leader against a rebellion.
Under a presidential decree that comes into effect Friday, a midnight to 6:00 am curfew already in place in Ndjamena since rebels tried to storm the capital this month will be widened to the whole country.
The decree authorised "house searches and controls on the private and public press."
A rebel alliance briefly took large parts of Ndjamena and surrounded Deby in the presidential palace on February 2-3, but government troops -- given logistical and intelligence support by the French military -- repulsed the rebels who have since withdrawn to the southeast.
French armed forces delivered Libyan ammunition to the Chadian army to help it repel the rebel assault, French defence ministry spokesman Laurent Teisseire acknowledged in Paris.
"French forces took part in the delivery of ammunition destined for the Chadian forces" during the rebel assault, Teisseire told a press conference.
He did not give details of the type of ammunition but said it had come from Libya.
France, the former colonial power, has 1,450 troops plus Mirage jet fighters in Chad, but Defence Minister Herve Morin insisted that France did not "participate directly in combat".
"We had to protect the (Ndjamena) airport," where French troops were evacuating hundreds of foreign nationals, Morin told France 24 television.
"Of course we responded every time we felt that the control of the airport might be at risk, but it was never an offensive action on our part."
"We did not participate militarily, directly in combat, except to ensure our own defence or the safety of the nationals that we evacuated," Morin said.
Meanwhile one of three Chadian opposition leaders missing since the weekend of unrest has been found alive, Interior Minister Ahmat Mahamat Bachir announced.
"We have just found Lol Mahamat Choua, who is alive. I cannot give you more details at the moment," Bachir said.
Mahamat Choua is a former head of state and before his disappearance was head of a committee implementing democratic reforms.
The opposition says he and two others were arrested by uniformed armed men at their homes in the aftermath of the battle for Ndjamena.
The reported arrests drew international criticism, with France, the EU and rights group Amnesty International expressing fears for the lives of the missing politicians.
The interior minister gave no further information on the other two missing, Ibni Oumar Mahamat Saleh, spokesman for the opposition alliance, and veteran opposition leader Ngarlejy Yorongar.
Chad's main opposition coalition has condemned a probe into the disappearances announced by the interior minister saying it was an attempt "to absolve the government" and Deby.
In the face of international criticism, Bachir on Wednesday said a judicial inquiry had begun and that he hoped to find the missing men as "soon as possible".
The opposition Coordination of Political Parties for the Defence of the Constitution (DPDC) said all three men were detained by Deby's presidential guard on February 3.
The government was initially silent about the disappearances of the three.
However, opposition and family members spoke of violent raids on their homes in which troops opened fire.
Mahamat Choua's party, the Assembly for Democracy and Progress, has expressed fears that Deby will take advantage of the unrest to "bury" an agreement with the opposition last August on organising new elections by 2009.