TALLAHASSEE, Fla. (AP) _ A pipe bomb exploded Wednesday in a building at Florida A&M University, the second blast at the historically black school in less than a month.

No injuries were reported. Damage was minor.

Warning calls were received before both explosions, but investigators would not provide any details about Wednesday's call.

In the Aug. 31 blast, a caller said he wanted to ``get rid of some of them niggers.'' No one was hurt and there was little damage from that blast.

Authorities also received a call Wednesday warning of a bomb in another campus building, but a search turned up nothing.

``There are obvious, common-sense connections you could make,'' said Byron Price, FBI supervisor in Tallahassee. But he added that authorities have no concrete evidence linking the two explosions.

Authorities have offered a $10,000 reward for information leading to an arrest and conviction in the first bombing.

The bomb that went off Wednesday exploded in a first-floor restroom of Perry Paige Hall, which has four floors of laboratories, offices, classrooms and the Navy ROTC office.

Florida A&M has about 12,000 students and 119 buildings on its campus.

Jackson said the school stepped up security after the first bomb and will tighten it even more now.

Some students said they no longer feel safe on campus.

``It's scary,'' Olevia Robinson said. ``The next time someone might definitely get hurt.''