Vandalism, harassment and other actions targeting mosques in the United States became far more frequent in 2015 compared to the previous year, a new report released Friday found .

The study by the Council of American-Islamic Relations (CAIR) found 71 hostile actions against Muslim houses of worship this year ­— including a march by armed protesters at a mosque in Richardson, Texas, in November and the placing of a severed pig’s head outside a mosque in Philadelphia earlier this month.

The total for 2015 is more than three times that in 2014. But CAIR said the actual number of incidents is probably far higher because many are not reported to the police or press.

“When I visit mosques, they will tell me all about the types of calls they’ve been getting,” said CAIR’s Corey Saylor, referring to threats and hate speech. “Many of the things they tell me about should absolutely get reported to law enforcement, but there’s desensitization because they’re so used to it by now, and they’ll just hang up or throw the letter out.”