Airport sources are saying that a secessionist group is to blame.
Approximately 500 soldiers from the FARDC armed forces were deployed around the Lubumbashi airport perimeter on Friday, following several hours of unsuccessful attempts to control the gunfire which first began at around 4:00 a.m. (0200 GMT).
Government spokesperson Lambert Mende told the AFP news agency that shooting could still be heard two hours after the initial attack.
According to witnesses, assailants took down a flag representing Monusco, a UN organisation which works to stabilise the region, and replaced it with their own red one.
Among the casualties are a mining company security agent, whose lifeless body was found not far from the main building at Lubumbashi airport, a witness told AFP. An officer of the FARDC was also wounded in the fighting. No other injuries have been reported.
Congo's Katanga region is one of the more stable areas of the country, with some of the richest sources of copper, cobalt and uranium.
As the central African country continues to recover from the 1998-2003 war, the east has fallen prey to rebel violence. A secessionist group called the Katanga Tigers, who fought in Angola in the 1960s, have resumed demands for a free Katanga.
A businessman told the Associated Press that flights had resumed by midday. Another witness, who requested anonymity, told the AFP that banks have closed. "Everything is calm in town, but students have been sent home."