MINNEAPOLIS (AP) -- Fire crews are evacuating a residential building near the University of Minnesota because of a suspected hazardous materials incident.

Authorities say the evacuation Tuesday in the Dinkytown area involves an  ``unconfirmed report of ricin,'' a deadly toxin. According to the Centers for Disease Control and Prevention website, ricin is a poison found naturally in castor beans, but it ``would take a deliberate act to make ricin and use it to poison people.''

Assistant Minneapolis Fire Chief Bryan Tyner says the substance was contained to one apartment unit. He says hundreds of students were displaced.

Fire crews arrived shortly after 4 p.m. and evacuated The Marshall, a building that caters to students, and sealed off the area.

A woman took herself to a hospital.

The building includes several retail outlets, including a Target.