* French armed forces launch Mali operation
* France's Hollande says 'cannot accept' rebellion
* Malian army launches counter-attack on rebel-held town
* Analyst says too soon for big push against rebels
France carried out air strikes against Islamist rebels in Mali on Friday as it began a military intervention intended to halt a drive southward by the militants who control the country's desert north.
Western governments, particularly former colonial power France, voiced alarm after the al Qaeda-linked rebel alliance captured the central Malian town of Konna on Thursday, a gateway towards the capital Bamako 600 km (375 miles) further south.
President Francois Hollande said France would not stand by to watch the rebels push southward. Paris, the leading advocate for foreign intervention in Mali, has repeatedly warned that Islamists' seizure of the country's north in April gave them a base to attack the West.
"We are faced with blatant aggression that is threatening Mali's very existence. France cannot accept this," Hollande said in a New Year speech to diplomats and journalists.
The president said resolutions by the United Nations Security Council, which in December sanctioned an African-led military intervention in Mali, mean France is acting in accordance with international law.
A military operation had not been expected until September due to the difficulties of training Malian troops, funding the African force and deploying during the mid-year rainy season. However, Mali's government appealed for urgent military aid from France on Thursday after Islamist fighters took Konna.
The rebel advance caused panic among residents in the towns of Mopti and Sevare, 60 km (40 miles) to the south, home to a military base and airport. Calm returned, however, after residents reported Western soldiers and foreign military aircraft arriving at Sevare airport from late on Thursday.
French Foreign Minister Laurent Fabius confirmed that France had carried out air strikes against the rebels. He would not reveal further details of the intervention - such as whether French troops were on the ground - while it was in progress so as to limit the rebels' knowledge of the operation.
EU foreign policy chief Catherine Ashton called for "accelerated international engagement" and said the bloc would speed up plans to deploy 200 troops to train Malian forces, initially expected in late February.
Military analysts, however, voiced doubt whether Friday's action heralded the start of the final operation to retake northern Mali - a harsh, sparsely populated terrain the size of France - as neither the equipment nor ground troops were ready.
"We're not yet at the big intervention," said Mark Schroeder, director for Sub-Saharan Africa analysis for the global risk and security consultancy Stratfor. He said France had been forced to act when the Islamists bore down on Sevare, a vital launching point for future military operations.
"The French realised this was a red line that they could not permit to be crossed," he said.
STATE OF EMERGENCY
More than two decades of peaceful elections had earned Mali a reputation as a bulwark of democracy in a part of Africa better known for turmoil - an image that unravelled in a matter of weeks after a military coup last March that paved the way for the Islamist rebellion.
Mali is Africa's third largest gold producer and a major cotton grower, and home to the fabled northern desert city of Timbuktu - an ancient trading hub and UNESCO World Heritage site that hosted annual music festivals before the rebellion.
Interim President Dioncounda Traore, under pressure for bolder action from Mali's military, declared a state of emergency on Friday, a presidency official told Reuters. Traore will fly to Paris for talks with Hollande on Wednesday.
The chief of operations for Mali's Defence Ministry said that Nigeria and Senegal were among the other countries providing military support on the ground. Fabius said these countries had not taken part in the French operation.
A spokesman for the Nigerian air force said planes had been deployed to Mali for a reconnaissance mission, not for combat.
A spokesman one of the main groups in the Islamist rebel alliance said they remained in control of Konna.
Asked whether the rebels intended to press ahead to capture Sevare and Mopti, the Ansar Dine spokesman, Sanda Ould Boumama, said: "We will make that clear in the coming days." He said French intervention was evidence of an anti-Islam bias.
The French foreign ministry stepped up its security alert on Mali and parts of neighbouring Mauritania and Niger on Friday, extending its red alert - the highest level - to include Bamako. France has 8 nationals in Islamist hands in the Sahara after a string of kidnappings.
"Due to the serious deterioration in the security situation in Mali, the threat of attack or abduction is growing," the ministry said in its travel alert.