
Armed police were hunting the man inside the home in the village of Montferrier-sur-Lez near Montpellier, which is home to around 70 men and women who have served as missionaries in Africa.
The man was wearing a mask and carrying a sawn-off shotgun and a knife, the sources said.
Fifty-nine of the residents were brought to safety, sources said, but others remained inside the home as police continued to search for the man.
Local authorities said it was a "criminal act" and the man's identity was unknown.
"A large number of security forces, firefighters and ambulance personnel are at the scene," the mayor of Montferrier-sur-Luz, Michel Fraysse, told AFP.