The military launched an offensive last month against the rebels
The government of Mali says its army has now taken control of all the bases of the most active Tuareg rebel group.
Rebel chief Ibrahim Ag Bahanga had fled while 22 of his men had been seized along with a large amount of munitions, a defence ministry statement said.
However, a spokesman for Mr Bahanga's movement told the BBC this was not true and no bases had been attacked.
The military launched an offensive in early January against the rebels in the north-east of the country.
Several hundred of his followers had reportedly joined other Tuareg rebel factions which recently returned to Algerian-brokered peace talks.
Mali's government wants the rebels to give up their demands for autonomy in the Kidal region, and promises to invest in areas inhabited by the Tuareg nomads.
"All the operational and logistical bases of the group of Ibrahim Ag Bahanga have been taken and are under the control of our army and security forces," the ministry said in a statement quoted by AFP news agency.
But rebel spokesman Hama Ag Sid'Ahmed said the statement did not "make any sense".
"None of our bases have been attacked. The only outposts that the army has taken were held by Algerian traders and these were taken more that two weeks ago," he told the BBC.
The BBC's Martin Vogl in the Malian capital, Bamako, says the army has had the rebels on the run for the last few weeks but it is difficult to check claims from either side given that much of the alleged action is taking place in the most remote areas.
The army launched its operation against Mr Bahanga after his group raided a military base in northern Mali in December, leaving at least 20 people dead.
Both sides signed a peace deal in 2006 in Algiers, but clashes continued in the north.
Three rebel groups recently united and said they would return to the peace process, denouncing Mr Bahanga's group.
The Tuaregs, a historically nomadic people living in the Sahara and Sahel regions of North Africa, have had militant groups in Mali and Niger engaged in sporadic armed struggles for several decades.