Police in West Miami and Washington, D.C., are under special alert after an unspecified threat was issued against Florida Republican Sen. Marco Rubio, Fox News Latino is reporting.

The news outlet said U.S. Capitol police have confirmed there is an “open and joint investigation” with local police over the threat but would not provide details about the threat’s potential severity.

West Miami police also confirm a “watch order” was issued for Rubio’s West Miami residence after the threat was considered credible enough to warrant extra security protection for the property in a suburban area of Miami–Dade County. The extra security began Tuesday afternoon, Fox News Latino reported.

It was unclear whether Rubio was at home Tuesday. He campaigned Monday night with likely Republican presidential nominee Mitt Romney in Pennsylvania and was scheduled speak Wednesday at the Brookings Institution think tank in Washington.

See the full report here