Police in Austin, Texas believe 3 package bombs are related.
Interim Police Chief Brian Manley added that evidence suggests the three packages are linked, leading authorities to believe a serial bomber is on the close in the state's capital.
Two people have been killed, and three others have been injured.
But police are still piecing together a motive for the bombings, though evidence suggests they are hate crimes.
All of the victims have either been African-American or hispanic.
The packages were delivered to residencies in the Austin area, with explosives packaged in delivery boxes.