Bamako:
French troops will be in direct combat against Islamist fighters in Mali within "hours", the country's army chief said Wednesday, as France's ground forces pushed north towards rebel-held territory in the six-day old offensive.
"The ground operation began several hours ago," Admiral Edouard Guillaud told Europe 1 radio. "In the coming hours - though I cannot say for sure if it will be one, or 72 hours - we will be in direct combat," he added.
A first contingent of 190 Nigerian troops was due to arrive in Bamako on Wednesday as part of a regional force of over 3,000 soldiers from Benin, Ghana, Niger, Senegal, Burkina Faso and Togo, to shore up the French air and ground offensive launched on January 11.
As French armoured units and Malian government forces headed north, a detachment was sent to secure a strategic bridge on the Niger river near the town of Markala in western Mali which leads to the capital Bamako.
"Our mission is to hold this bridge to prevent the enemy from accessing the south," said Colonel Frederic of the 21st marine infantry regiment from Chad. He asked that his full name not be used.
A military source said the Islamists were some 80 kilometres (50 miles) north of Markala, putting them around 350 kilometres away from Bamako.
A convoy of armoured vehicles were also reported by a local government official to be heading to the town of Diabaly, which Al Qaeda-linked groups seized earlier this week.
French Defence Minister Jean-Yves Le Drian confirmed that the troops, whose number is set to triple from 800 at present to 2,500 men, faced a long and tough battle against determined fighters whose number he estimated at up to 1,300.
"It's a little more difficult in the west, where we have the toughest, most fanatical and best-organised groups. It's under way there but it's difficult," he said.
President Francois Hollande vowed his forces would crush the Islamist militia.
"What do we plan to do with the terrorists? Destroy them. Capture them, if possible and make sure that they can do no harm in the future," he said on Tuesday during a visit to the United Arab Emirates.
West African army chiefs in Bamako were expected to resume talks on Wednesday on the roll-out of the UN-mandated regional intervention force in the former French colony.
Mali has been effectively split in two since March 2012, when Islamists took advantage of a short-lived coup in Bamako and an offensive launched by Tuareg separatists in the north to seize half of the country.
Western countries had voiced fears that Mali's north -- a desert region larger than France -- could become Al-Qaeda's leading global safe haven and be used to launch attacks on targets in Europe.
However a proposed African-led intervention remained mired in indecision after months of planning, and the Islamists last week pushed into the government-held south, seizing the town of Konna.
The advance on the capital prompted France to intervene, a decision which has been widely supported at home and in the international community, which has offered logistical support but no military back-up on the ground.
Aboul Habib Sidi Mohamed, a spokesman for one of the Islamic rebel groups Ansar Dine (Defenders of Faith) which seized Konna, said their goal was "to protect the population" after a failure to negotiate with government.
'Jihadists in it for the long haul'
Faced with the French air offensive, Islamists have fled key northern stronghold towns, including ones where they had imposed their brutal version of Islamic law.
But analysts have warned the withdrawal was likely a tactical move.
"The jihadists are in it for the long-haul. They are comfortable in this situation: the vast desert, a difficult terrain, a precarious security situation," said Tunisian Islamist expert Alaya Allani.
One resident in the northern town of Gao reported that the Islamists had cut telecommunication links late Tuesday, rendering land lines and mobile phones useless.
"They accuse residents of giving information to the (French) soldiers," he told AFP by satellite phone.
The UN and aid agencies have also expressed fears for civilians caught up in the conflict.
So far 144,500 refugees have fled the unrest to neighbouring Mauritania, Niger, Burkina Faso and Algeria, the UN humanitarian agency said Tuesday, while another 230,000 were internally displaced.
Belgium offered two C-130 transport planes and two helicopters to back up France's offensive, while Britain and Canada have offered troop transporters. Germany is considering logistical or humanitarian support.
Hollande stressed however that French troops would not be in Mali for good but would stay until security had been restored and the "terrorists" eliminated.
At home, France has deployed 700 troops in and around Paris, indicating mounting concern over potential reprisal attacks after threats by the Islamists to "strike at the heart" of France.