A package received by the Arizona Supreme Court tested positive for a "homemade explosive substance," authorities said Monday.

The State Courts Building and other buildings near downtown Phoenix were evacuated around 8 a.m. local time Monday while authorities investigated a suspicious package that contained multiple vials, the Arizona Department of Public Safety and the state Supreme Court said in a joint statement. Two of the vials tested positive for a "homemade explosive substance."

The courts building was closed as authorities performed safety sweeps.

The package was later placed in a secure vehicle and driven away from the area, CBS affiliate KPHO-TV reported. A Department of Public Safety spokesperson said it will be disposed of.

Court officials told KPHO-TV the package didn't have a return label. Authorities said an investigation was underway and more information will be shared when available.