Idriss Deby has accused Sudan of being behind the coup bid

In a speech broadcast on state media, Idriss Deby said the emergency powers would be in effect for 15 days.

They include a night-time curfew and controls on the movement of vehicles.

The rebels, who Chad claims are backed by Sudan, were driven from N'Djamena after two days of fighting and back towards the eastern border with Sudan.

Meanwhile, one of three missing opposition leaders has been found, according to Interior Minister Ahmat Mahamat Bachir.

We left our houses and took to the streets to say hello to the rebels. We can't go back now

Emmanuel, student

In pictures: Chad refugees

Earlier this week, France and human rights groups expressed their concern after the three disappeared during the fighting.

France has also acknowledged that its forces transported weapons to Chad's army as it beat back the rebel assault.

The former colonial power said it had acted in accordance with a military co-operation agreement between the two countries.

Scared

Mr Deby said the emergency decree instituted "measures important and urgent to maintain order, guarantee stability and assure the good functioning of the state".

It also authorised "house searches and controls on the private and public press".

One of the 30,000 people who fled Chad to Cameroon told her that some people had welcomed the rebel advance.

"We left our houses and took to the streets to say hello to the rebels. We can't go back now," said a young student called Emmanuel.

"The government forces are going from house to house mistreating us civilians because we cheered for the rebels."

The assault began on 2 February, when the rebels seized control of large parts of the capital, approaching the palace where Mr Deby was holding out.

The Red Cross said more than 160 people were killed and 1,000 injured in the fighting.

Mr Deby has accused Sudan of being behind the coup bid.

Chad says Darfur wants to delay the deployment of an EU peacekeeping force to Chad, to safeguard refugees from Darfur.

But Khartoum has denied the allegations and in turn accuses Chad of backing rebels in Darfur.

The deployment of the 4,000-strong EU force was delayed by the rebel attacks but is now due by the end of February.

Mr Deby seized power in a coup in 1990, but has won three elections since then, although their legitimacy has been challenged.