Police arrested several protesters after they managed to get into the center, and had to stand guard near the building, local newspaper Ouest-France reported.
The demonstration was staged by far-right groups, with support from local residents taking part.
Protest coordinators with loudspeakers could be seen encouraging members of the protest into action.
It follows confirmation from the regional prosecutor that a 67-year-old local woman had been sexually assaulted by a 16-year-old Sudanese migrant last Thursday. The “youth” had been staying in the migrant center in the village, moving there after the dismantling of the Calais Jungle camp.
The far-right activists accused the authorities of trying to sweep the incident under the carpet, especially after the prosecutor said that the situation had been exaggerated online.
“The victim was taking the shopping out of her car when she was approached by a young man. In broken English he told her that her house was beautiful. Then he tried to kiss her repeatedly, after which she pushed him back,” prosecutor Francois Touron told Ouest-France.
“The young man, from Sudan, touched the woman’s left breast, then he made a gesture as if he was masturbating” the official added.
The woman went to police and the migrant was detained and charged with sexual assault. However, the authorities later released him, and he is set to appear in court in March.