More than 400 hate crimes were recorded against France's Muslim community in 2015, three times as many as the 133 reported the year before.
The figures come from Dilcra, a government body tasked with monitoring racism in France, and were published by Le Parisien on Wednesday.
"This is a dramatic and very worrying development, which can mainly be explained by the surge in anti-Muslim acts after the January attacks," Dilcra head Gilbert Clavreul told the paper.
Indeed, directly after the January attacks at the Charlie Hebdo offices in Paris, over 100 anti-Islam incidents were reported in the first two weeks alone.
The crimes included vandalism at mosques - some of which were torched and targeted by graffiti - but also anything from discrimination and harassment to assaults against people of Muslim faith.
Around three quarters of the Auch mosque were damaged by a blaze in August. Photo: AFP
Abdallah Zekri, the president of the National Observatory against Islamophobia, said the unprecedented figures in 2015 likely didn't even paint the full picture, estimating that 15 percent of Muslim victims think there's "no point" in reporting the crimes.
"People are very worried in the religious community," he told Le Parisien, highlighting cases of women having their headscarves pulled off, and one woman who was severely beaten.
The full figures for the entire year are still not available, but the figures are almost certain to higher when the recent attacks in Corsica are taken into account.
Over the Christmas period, demonstrators vandalized a Muslim prayer hall and trashed copies of the Koran after an assault on firefighters.
Around 1,000 out of France's 2,500 mosques are guarded by police or soldiers.