Rubio's DC headquarters briefly evacuated | TheHill

Marco RubioMarco RubioKasich makes general election pitchTrump to skip second Fox News debateTrump predicts 'riots' if he's not nomineeMORE's Washington, D.C., headquarters is being evacuated after staffers found an unidentified white substance in the building, according to multiple reports. 

Alex Conant, a spokesman for the Republican Florida senator, told ABC News that campaign staff had evacuated to the roof and said HazMat crews were responding.

But a short time later, Rubio staffers tweeted that the headquarters was given the all-clear and said they are heading back into the building. The scare came just hours before GOP presidential primary polls close in five states voting Tuesday, including the senator's home state of Florida.  

—Updated 5:51 p.m.