Suspected jihadists killed two Malian soldiers overnight in the country's unstable north, military sources said Monday, adding that they also attacked a police station.

Mali's deteriorating security situation is of growing concern as Al-Qaeda-linked groups mount increasingly deadly attacks on domestic and foreign forces.

"Terrorists on motorbikes opened fire" on two soldiers from the National Guard at Gossi, south of Gao, a major city in the region, a military source told AFP.

Another source said the two men were shot in the head.

On Sunday evening, suspected jihadists also attacked a police station at Hombori, about 90 kilometres (55 miles) south of Gossi.

"The army responded. To the best of our knowledge, there are no victims," a security source told AFP.

At least four civilians were killed in the north on Friday and Saturday and authorities have banned motorbikes and pick-up trucks in some areas to prevent further jihadist attacks.

Such vehicles are often used by Islamist fighters, in the north and the centre of the country.

The ban applies to a dozen "circles" in the central regions of Segou and Mopti and northwest Timbuktu region, a military statement said.

Islamic extremists linked to Al-Qaeda took control of the desert north of Mali in early 2012, but were largely driven out in a French-led military operation launched in January 2013.