The pigs' heads were found hung on an entrance gate of the mosque in the town of Montauban, shortly before morning prayers Wednesday, Radio France Internationale reported. A large amount of pig blood was also found spilled on the ground
Muslims, who are currently observing the holy month of Ramadan, consider pigs to be unclean.
"It is contemptible," said the mosque's president, Hajii Mohamed. "To attack a religion like this, I don't know what is happening. People lose their heads, especially during Ramadan."
This is the first such incident in the southern Tarn-et-Garonne region where Islamist terrorist Mohamed Merah killed three paratroopers, three Jewish schoolchildren, and a rabbi before he was killed by police.
France's Union of Jewish Students said it was appalled by the incident and that it occurred in a "worrying climate of hatred".
Interior Minister Manuel Valls condemned the act in a letter to the desecrated mosque. "I can only be outraged in the face of such a revolting act that strikes a blow to the dignity of the Muslims of France," he said