Shots were still being heard in the area, a source in the UN peacekeeping force in Mali (MINUSMA) told AFP, indicating hours-long fighting.
"Six to seven terrorists arrived very early in the morning at a MINUSMA camp in Timbuktu. They blew up their vehicle before attacking the camp with mortars," the source said.
"One peacekeeper from Niger was wounded." the source said, adding that the camp had recently been evacuated by blue helmets from Niger but some soldiers had remained there.
A Malian military source said Malian troops were "fighting to neutralise the terrorists."
Some hours later the UN mission to Mali said that Malian forces backed by UN helicopters had retaken a police base in Timbuktu from unknown assailants who had captured it early in the morning.
"It's over now," said spokesman Olivier Salgado, without saying whether there had been casualties.
They are now inspecting the site and looking for explosive devices," he added.
Also it is reported that Gunmen Stormed the Palmeraies Hotel in Timbuktu in Mali
Northern Mali fell under the control of Tuareg rebels and terrorist groups linked to Al-Qaeda in 2012.