Hundreds of Malian and French troops were en route Tuesday afternoon to the western town of Diabaly, which Islamists seized the day before, prompting airstrikes from French fighter jets overnight, witnesses said.

"Several hundred Malian and French soldiers left Niono (south of Diabaly) to take" back the town, said a local government official in Niono.

The move would be the first time French ground troops engage in the battle with Islamists, which they have waged up until now with fighter jets targeting the insurgents' bases.

"Our French brothers are currently with us in Niono on their way to Diabaly. Tomorrow we will take back Diabaly with the French," a Malian security source said, on condition of anonymity.

The procession of troops in armoured vehicles was cheered on by residents of the town as they passed by, according to witnesses.

The Islamists, led by Al-Qaeda in the Islamic Maghreb (AQIM) leader Abou Zeid, seized the town, which lies 400 kilometres (250 miles) north of the capital, on Monday.

Overnight, French fighter jets launched strikes on the town, and residents of a town some 20 kilometres away reported seeing some of the Islamists fleeing.

A regional security source confirmed however that the insurgents were still in the zone around the town, some of whom had taken hostage a local government official and his family.

Meanwhile a convoy of some 30 French tanks left Mali's capital on Tuesday afternoon, headed in a northern direction, an AFP journalist said.

The armoured vehicles were seen leaving Bamako's airport, where they had been stationed, but their destination could not be confirmed.