It held Norwegian officers arrested in 1942 and 1943.
The fort is still a military area, but is today only used as an administration building for the Norwegian naval officers training school.
Some 20 Norwegian officers lost their lives as a result of their service in the Congo.
Later in the day a Norwegian officer approached Schmidt asking for his surrender, but was rejected.
The Norwegian senior officers, most of whom have been at sea since age 15, are beguilingly mad-looking.
Earlier this morning, he met with British and Norwegian officers.
He studied there for a year before being enrolled in the Norwegian officers' training school.
Norwegian officers were coerced into carrying through the executions.
The classes have a tradition of taking names from Norwegian officers, inspiring the cadets to follow in their paths.
He later returned to Norway and painted Norwegian naval officers.