Fighting is continuing in Chad after rebels attacked an army garrison near the borders of Sudan and the Central African Republic.
The Chad rebels want to oust Idriss Deby's government
Chad government officials said a convoy of what they called mercenaries had launched the assault on the garrison.
United Front for Democratic Change (FUCD) rebels confirmed the attack, and said they had seized two other towns but this was denied by the government.
Chad says Sudan is backing the rebels, but Sudan denies this accusation.
A large number of army officers have deserted to join FUCD, the coalition of rebel groups led by Mahamat Nour from bases in Darfur on Sudan's border with Chad.
"This is only the beginning - our morale is very high," Abdel Rahman Abdel Karim, one of the rebel FUCD leaders, told Reuters news agency by phone after the attack on the Haraze Mangueigne garrison.
Fighting had lasted one hour with only four men injured and 50 prisoners were taken, the rebel leader told the agency.
An unnamed Chad military source quoted by Reuters said the attackers had not got beyond Haraze Mangueigne, and refuted rebel claims to have taken the towns of Am Timane and Abou-Deia.
"Neither Am Timane nor Abou-Deia is affected and they are not under the control of rebel units. For now the security forces are at Haraze Mangueigne," the source said.
Chad launched a military operation against rebels three weeks ago, in the course of which the country's most senior military commander was killed.
In February, Chad and Sudan signed an accord to resolve their differences over fighting along the border.
The FUCD is seeking to overthrow President Idriss Deby, who seized power in 1990 after launching a rebellion from bases in Darfur.