Jihadists launched a shooting rampage in the Radisson Blu hotel in the centre of the Malian capital Bamako on Friday, security sources and an AFP journalist said.
Automatic weapons fire could be heard from outside the 190-room hotel, where security forces have set up a security cordon.
"It's all happening on the seventh floor, jihadists are firing in the corridor," a security source told AFP.
The shooting follows a nearly 24-hour siege and hostage-taking at another hotel in August in the central Malian town of Sevare.
Four soldiers, five UN workers and four attackers were killed.
Islamist groups have continued to wage attacks in Mali despite a June peace deal between former Tuareg rebels in the north of the country and rival pro-government armed groups.
Northern Mali fell in March-April 2012 to Al-Qaeda-linked jihadist groups long concentrated in the area before being ousted by an ongoing French-led military operation launched in January 2013.
Despite the peace deal, large swathes of Mali remain beyond the control government and foreign forces.