Terror attack ... Two jihadists have taken 140 hotel guests and 30 employees hostage in South Africa. Picture: Supplied

The US embassy in Bamako, the capital of Mali, raised alarm of an “ongoing active shooter operation” at the Radisson Hotel on Twitter.

The embassy warned all staff and US citizens to find shelter, and to contact their families.

Automatic weapons could be heard firing from the 190-room hotel, which has been cordoned off by security.

A security source told Associated Press that everything is happening on the seventh floor of the building.

“Jihadists are firing in the corridor,” the security source said.

In a statement, the hotel chain said they were aware of the hostage situation.