Story highlights FBI is the lead investigative agency

Lawmakers speaks of "uptick" in anti-Muslim crime

(CNN) Minnesota's governor declared that the explosion at a mosque outside Minneapolis over the weekend was "an act of terrorism."

An improvised explosive device caused an explosion at the Dar Al-Farooq Islamic Center in Bloomington, the FBI said.

Gov. Mark Dayton denounced the act at a news conference on Sunday.

The FBI is the lead investigative agency and said it is working on determining who set off the explosive and why. The Minneapolis office has not made a declaration of terrorism but Rick Thornton, the special agent in charge of the Minneapolis office, called the investigation "our top priority."

The Islamic center said on a GoFundMe page that the FBI says Saturday's blast "was caused by 'destructive device' in a suspected hate crime." The center is raising money for repairs to damage caused by the blast.

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