An envelope delivered to the Toledo Police Department in Ohio has reportedly exploded, FOX Toledo reported.

At least two officers were hurt in the blast, which happened just after 2 p.m. on the fourth floor. Both were decontaminated and were being treated at the hospital.

The envelope was sent to the station's detective bureau, according to FOX Toledo. It had a Washington Township return address.

The fourth floor of the station was locked down after the incident. Fire, FBI and bomb officials were investigating.

Click here for more on this story from FOXToledo.com.