* Officers involved in coup protest in southern barracks
* Government frees rebel prisoners to stem wave of violence
* Dual challenge for new president after coup, occupation (Recasts with president's speech)
By Tiemoko Diallo and Adama Diarra
BAMAKO, Oct 2 (Reuters) - Mali's new president, Ibrahim Boubacar Keita, on Wednesday dissolved an army reform committee dominated by former members of a military junta after blasting disgruntled officers for staging an unruly protest at a military base earlier this week.
Officers who participated in a military coup last year fired into the air on Monday in the southern garrison town of Kati, close to the capital, Bamako, in protest at not receiving promotions they said had been promised.
Their former leader, Captain Amadou Sanogo, was named head of the Committee for Reform of the Armed Forces and was later promoted to four-star general by a transitional government, in what diplomats said was an effort to encourage him to retire.
The protest took place as soldiers traded fire with Tuareg MNLA separatists in the remote northern town of Kidal, underscoring the dual challenge facing Keita's new government.
"I will not tolerate indiscipline and anarchy," Keita said in a speech broadcast on state television.
"Investigations are under way into the reasons and the individuals behind this slap in the face of the nation which comes at a time when soldiers from other nations have left their countries ... to come defend us," he said.
Keita said he had ordered the immediate dissolution of Sanogo's military reform committee.
The March 2012 coup, triggered by the government's failure to tackle a Tuareg uprising, ushered in an Islamist occupation of northern Mali.
France launched an operation in January that killed hundreds of al Qaeda-linked fighters and ended their northern occupation, but allowed the MNLA to remain in Kidal, saying their revolt was a domestic political issue.
France aims to wind down its troop presence to 1,000 by the end of the year. But violence has flared again in northern Mali since the MNLA abandoned a June ceasefire last week.
A grenade attack that wounded two soldiers in Kidal on Friday was followed by two days of clashes that began on Sunday.
Mali's government freed 23 rebel prisoners on Wednesday under terms of the ceasefire deal in an effort to revive the stalled peace process.
Prosecutors ordered the arrest this year of dozens of Tuareg and Islamist insurgents who participated in the seizure of the north of Mali last year.
Justice Minister Ali Bathily said the government hoped the release of the rebel prisoners would help calm the situation.
"With the aim of bringing peace, we have released these prisoners," he said at a ceremony in Bamako. "They will not be pursued for crimes against humanity or war crimes."
The government had already freed 32 prisoners under the truce accord, which was signed in Ouagadougou, the capital of neighbouring Burkina Faso.
Albert Koenders, head of the 12,600-strong U.N. peacekeeping mission in Mali, urged both sides to return to the negotiating table.
"The liberation of this group of prisoners, it's an important step. ... It should be followed, of course, by other measures to restore confidence and restart talks," he said, calling for rebel forces to return to barracks and disarm.
Mohamed Ag Intallah, the Tuareg clan chieftain of Kidal who attended the ceremony, called on Keita's government to do more to honour its commitments under the Ouagadougou accord.
"This is a big step, but much remains to be done because the most important prisoners are not the ones here," he said. "I am waiting for the freeing of those people." (Reporting by Tiemoko Diallo and Adama Diarra; Writing by Daniel Flynn and Joe Bavier; Editing by Mark Heinrich and Peter Cooney)