BAMAKO — French troops launched a ground operation against Islamist fighters in Mali, France’s defence chief said on Wednesday, as they pushed north towards rebel-held territory in the six-day-old offensive.

"The ground operation began several hours ago," Adm Edouard Guillaud said Wednesday. "In the coming hours — one or 72 hours — we will be in direct combat."

The first contingent of 190 Nigerian troops was due to arrive in Bamako yesterday as part of a regional force of more than 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.

Germany said it would supply two Transall military transport aircraft, joining the UK, which has already sent C-17 transport aircraft. The US is sending drones, as well as communications and logistical support.

Alex Vines, research director at think-tank Chatham House, said the slow African response to the Mali crisis was an acknowledgement that "African solutions to African problems" was not always applicable and that some crises were truly global and needed international support.

"The regional body, the Economic Community of West African States, has no capacity to conduct warfare in terrain like that of northern Mali, despite last year’s UN (United Nations) Security Council-backed plan to deploy 3,000 troops later this year," Mr Vines said.

"There is an opportunity here for the African Union (AU) to rebuild its relationships with North African states (soured by Libya’s civil war in 2011) and with key international partners such as France, the EU (European Union), Nato (North Atlantic Treaty Organisation) and others. Unlike on Libya in 2011, the AU has supported international action on Mali. Nkosazana Dlamini-Zuma, the new South African AU Commission chairwoman, questioned whether the UN is adequately equipped to deal with the complexities of the conflict in Mali and the Sahel. However, she and other African leaders have accepted the urgency of an effective military response to the crisis."

Adm Guillaud said French military strikes were being hampered because militants were using the civilian population as a shield.

French Defence Minister Jean-Yves le Drian confirmed that the troops faced a tough battle against about 1,300 fighters.