A fire that broke out at a Connecticut mosque over the weekend has been ruled an arson.

“This was intentionally set,” said New Haven Fire Chief John Alston at a Monday press briefing.

“We are taking this very serious,” added interim Police Chief Otoniel Reyes. “We are working with our federal and state partners to make sure that there is no underlying issue to the greater community and to the greater religious community.”

The multi-story blaze started on the first floor of New Haven’s Diyanet Mosque on Sunday and eventually spread to the second. At least one person was inside when the fire was reported at around 4 p.m., officials said, but they were able to make it out unscathed.

Locals have been celebrating the Islamic holy month of Ramadan and visiting mosques in droves.

“Any time there’s an event like this in a house of worship, anywhere in the United States, it triggers a response of both the ATF, the FBI and state and local authorities,” Alston said. “That has happened.”

Gov. Ned Lamont described the mosque fire as a “hateful” attack.

“I find an attack like this is especially hurtful and hateful when you attack an institution for what people believe and you attack a religious house of worship,” he said at the afternoon press briefing. “The one thing I find hopeful, as I heard from the imam, is that other houses of worship, churches and synagogues, have stepped forward and said, ‘We want to help.’”

Connecticut’s first Muslim state lawmaker, Sen. Saud Anwar, condemned the fire as a “heinous” act of arson — saying it serves as a “reminder of those in the world who wish to harm others solely due to their beliefs.”

“I am thankful that no one was harmed, but this act stands as another attack on religion,” he said. “We all must stand and rally together in the face of those who want to bring us apart. An attack on one of us is an attack on all of us.”

With Post wires