France has increased its troop strength in Mali to 1,400 to help fight militant Islamists in the north, the French defence minister has said.
France said it launched military action in its former colony last Friday to stop it becoming a "terrorist state" after a rapid advance by the Islamists.
Heavy fighting has been continuing, with French forces bombing Diabaly, 350km (220 miles) north of the capital.
Troops pledged by West African nations have also started arriving in Mali.
Some 100 Togolese soldiers landed in Bamako on Thursday, with 80 Nigerian troops expected shortly.
In Brussels, the EU foreign ministers agreed to press ahead with sending a team to train the weak Malian army.
"The actions of French forces, be it air forces or ground forces, are ongoing," France's Defence Minister Jean-Yves Le Drian said on Thursday.
"They took place yesterday, they took place last night, they took place today, they will take place tomorrow."
On Wednesday, French and Malian sources said their forces launched the first major ground operation against the militants, with street battles taking place in Diabaly.
But Diabaly's mayor, Oumar Diakite, told the BBC from Bamako only Malian troops were involved in the battle. Both sides suffered casualties, he said.
"The Islamists were burying their dead next to our cemetery in Diabaly. There were also three bodies of Malian soldiers lying on the side of the road," Mr Diakite added.
"The residents wanted to take the bodies and bury them, but they [the militants] would not let us."
Mr Diakite said French forces were in the nearby town of Niono. "They are co-ordinating with the Malian army," he said.
Well-armed Islamists entered Diabaly on Monday, taking the town from Malian forces.
French fighter jets have since attacked rebel positions.
France launched its operation last Friday, after the Islamists seized Konna and began advancing further south. It had some 800 troops in Mali, before the latest deployment.
Defence sources said their numbers were expected to increase to 2,500.
Nigeria - which has promised to send a total of 900 troops as well as fighter jets - will lead the West African force.
Chad has also confirmed 2,000 soldiers will join the anti-rebel operation in Mali.
Benin, Ghana, Niger, Senegal, Burkina Faso and Togo have also pledged to take part.
In total, 3,300 regional troops will be deployed in the conflict under a UN Security Council resolution.
France has been pushing hard for the deployment of West African troops and the arrival of the first Nigerian troops should bring some relief to French soldiers who are only getting limited support from the fairly weak Malian army, analysts say.
It is not yet known exactly what role the West African troops will play or how well prepared they are for what is expected to be a challenging ground assault against the Islamist militants.
The UK has provided transport planes, and on Wednesday Germany gave two transport planes as logistical support.
EU foreign ministers agreed at a meeting in Brussels on Thursday to send a military training mission to Mali.
No combat role is envisaged for it.
"The threat of jihadi terrorists is something that should be a matter of great concern to all of us," Dutch Foreign Minister Frans Timmermans said, ahead of the meeting, Reuters news agency reports.
"And there is not one European country that can hide if this threat would present itself to the European continent."
Islamist groups and secular Tuareg rebels took advantage of chaos following a military coup to seize northern Mali in April 2012. But the Islamists soon took control of the region's major towns, sidelining the Tuaregs.