Houston, December 28 (RHC)-- Two U.S. mosques have been attacked in separate incidents over the weekend. On Christmas Day, just after hundreds of people finished Friday prayers, a two-alarm fire erupted at the Islamic Society of Greater Houston in Texas. Authorities say it was intentionally set.

Meanwhile, officials in California’s Central Valley are investigating a Molotov cocktail attack on the Tracy Islamic Center as a possible hate crime.

A study earlier this month found hate crimes against Muslim Americans and U.S. mosques have tripled since the attacks in Paris and San Bernardino. 

The Council on American-Islamic Relations has reported more incidents targeting mosques this year than in any other year on record.