A major explosion has been heard in the northern Malian city of Gao, which French-led forces recently recaptured.
The blast went off at around 11pm and a French military source said it had happened some 10km from the French military base at the city's airport.
French-led forces retook Gao on 26 January after a campaign of French air strikes forced Islamist fighters there to flee.
But while some have fled into the desert wilderness further northeast, others have stayed in the bush surrounding the city, mingling with local residents sympathetic to their cause, French and Malian military sources said.
One Malian officer recently said that it was still dangerous for his troops to venture too far outside the city.
At dawn on Friday, a young suicide bomber blew himself up, slightly injuring a Malian soldier at the entrance to the city, in the first attack of its kind in the country.
And on Saturday morning, two young men carrying explosive belts were arrested near the city before they could set off their devices.
AAP reports that troops in the area have also been discovering landmines left by the insurgents.
In recent days mines have killed two Malian soldiers in one incident and four civilians in another.