Gunmen have launched an attack on the Radisson Blu Hotel in the centre of Mali's capital, Bamako, reports the BBC.
Two people have locked in 140 guests and 30 employees in "a hostage-taking situation", the hotel's owners said in a statement.
Police have surrounded the hotel, which the gunmen entered shooting, and shouting "God is great!" in Arabic, a security source told Reuters.
A BBC reporter says the US-owned hotel is popular with expats working in Mali.
A Chinese guest told China's state news agency Xinhua via a mobile app that he was among a number of Chinese guests trapped there.
In August, suspected Islamist gunmen killed 13 people, including five UN workers, during a hostage siege at a hotel in the central Malian town of Sevare.
France, the former colonial power in Mali, intervened in the country in January 2013 when al-Qaeda-linked militants threatened to march on Bamako after taking control of the north of the country.