Chad's government has denied reports that a large column of rebel vehicles is advancing on the capital, N'Djamena.
The French embassy had earlier warned that fighting near N'Djamena within the next 24 hours could not be ruled out.
It has now said the column is no longer progressing towards the city. The government has told people to stay calm as troops mass around the capital.
Earlier, the Chadian government said it had retaken two towns near the Sudanese border, a day after rebels seized them.
Abeche, about 700km (440 miles) east of N'Djamena, and the nearby town of Biltine, were captured by two different groups opposed to the rule of President Idriss Deby on Saturday.
One rebel leader said his forces had withdrawn from the town of Abeche after inflicting heavy losses on the army, and were preparing to strike again.
Government troops are reported to be massing around the capital
The leader of a second rebel group, the Rally of Democratic Forces (RAFD), told AFP news agency that his forces were still in control of Biltine, contrary to government claims.
His group was sending out patrols up to 100km west of the town, he said, rather than having a strategy to attack the capital.
An unnamed Chadian military source had earlier told AFP that the rebels advancing on N'Djamena were from the RAFD.
Speaking before the government announcement, the BBC's Stephanie Hancock in N'Djamena said that the capital was on full alert in fear of a rebel attack for the second time in as many months.
Some reports had warned between 100 and 120 vehicles could be on their way.
In a statement sent to the AFP news agency, the French embassy said: "The military situation changed swiftly at the end of the morning. The presence of a large rebel column has been confirmed in the Bata region of the country, heading west."
That sighting put the rebels at less than 400km from the capital.
However, the embassy later softened its advice to say the column "was no longer progressing" and that "the situation is normal in N'Djamena".
Nonetheless, a Chadian security minister told the BBC that government forces were preparing to deal with a rebel offensive, with army troops mobilised and massing outside N'Djamena.
Rebels last attacked the capital in April, when hundreds of people were killed before the offensive was repelled.
Last month rebels also threatened to approach the capital, but eventually turned round without attacking.
Chad's Defence Minister, Bichara Issa Djadallah, told the BBC that another rebel group, the Forces for Development and Democracy (UFDD), had fled Abeche on Sunday morning after the Chadian Army surrounded their positions.
Extensive looting took place in Abeche on Saturday night, and there are reports that at least three humanitarian compounds were targeted.
Abeche, about 160km from the Sudanese border, is the centre of a huge relief operation, to assist refugees from the conflict in Sudan's Darfur region.
About 200,000 refugees have crossed the border into Chad to escape the violence in Darfur.
The Chadian government has accused Sudan of backing the rebels - a charge Sudan denies - while Chad denies Sudanese claims that it supports black African rebels in Darfur.