By Adama Diarra
KIDAL, Mali (Reuters) - Mali sent in troops on Sunday to retake Kidal from Tuareg separatists who killed at least eight soldiers and captured around 30 civil servants while the prime minister was on a visit to the northern town.
Gunfire had already broken out before Prime Minister Moussa Mara's arrival early on Saturday and he was forced to take shelter in an army base as rebel fighters attacked and seized the regional governor's office.
"In light of this declaration of war, the Republic of Mali is henceforth at war," Mara told a Reuters reporter inside the base overnight.
He told a news conference on Sunday after he moved to Gao, another city in the north, the government had already sent troops, including special forces, to retake Kidal.
"Reinforcements are on the way to Kidal. The objective is to totally retake Kidal," a senior military source also told Reuters, asking not to be named.
Mara was visiting the town, a stronghold of Tuareg separatists, for the first time since his appointment last month as part of efforts to revive long-delayed talks with northern armed groups.
Mali was thrown into turmoil in 2012 when al Qaeda-linked Islamists took advantage of a Tuareg-led rebellion and seized control of the country's north before a French-led military operation, known as Serval, drove them back last year.
The government and a grouping of armed groups including the Tuareg MNLA, which broke with the Islamists ahead of the French offensive, signed an agreement last year promising to hold talks over autonomy.
But the clashes, potentially the worst pitting the government against Tuareg fighters since the French intervention, now threaten to sink efforts to find a peaceful solution to the long cycle of rebellions in the West African nation's desert north.
The flare up in a troublespot many had hoped had now been brought under control comes as West African nations and their international partners are redoubling efforts elsewhere to contain Islamist groups such as Boko Haram in Nigeria.
France, in particular, is seeking to redeploy part of its force in Mali to tackle the regional threat.
MINUSMA, a nearly 13,000-strong U.N. peacekeeping mission, is rolling out but is not yet at full strength in the region the armed groups call Azawad.
A spokesman for the National Movement for the Liberation of Azawad (MNLA) claimed control of Kidal on Sunday. He said the rebels were preparing to hand over the government workers.
"We aren't calling them hostages. They are survivors under our protection. They will be freed soon because they are civilians," Attaye Ag Mohamed told Reuters by telephone from the town.
He said the MNLA was also holding 15 soldiers it considered to be prisoners of war.
Mara criticized both the French and U.N. forces for allowing the attack to take place.
"The very least we'd expected from MINUSMA and Serval was that they'd ensure the governor's office wasn't attacked," he said.
MINUSMA said on Sunday 21 U.N. police officers were injured in the clashes while providing security for the prime minister's visit to Kidal. Two suffered from serious gunshot wounds. However the peacekeeping mission did not say who was believed to have started the clashes.
"These acts constitute a serious violation of the preliminary agreement and hamper efforts aimed at bringing peace and security to the regions of the north, particularly Kidal," it said in a statement.
Malian forces suffered 25 wounded in addition to the eight dead, according to the Defense Ministry, while 28 attackers were killed and 62 wounded.
A Malian military source said Saturday's gunbattle erupted after MNLA fighters in two trucks attacked an army checkpoint in front of the governor's office.
The MNLA's Ag Mohamed rejected the government's version of Saturday's events and said the army attacked first, opening fire on the group's barracks following pro-independence protests in the town.
He said the rebels had killed 19 government soldiers and suffered no losses of their own.
"The situation is calm right now. We're in position. We're not scared of the Malian army. We're ready," Ag Mohamed said.
(Additional reporting by Tiemoko Diallo and Joe Bavier; Writing by Joe Bavier; Editing by Alison Williams)