A college in Pennsylvania says the FBI is investigating an online threat against the campus by someone claiming loyalty to the Islamic State.

According to Lafayette College, Sunday shortly before 5 a.m., "an extensive room-by-room search" of the Easton campus turned up "no malicious or hazardous materials."

Officials say someone claiming to be a male student Saturday night threatened an attack with "pipe bombs, pressure cookers and nail bombs," saying his faith had been ridiculed.

The college says it was working with police and the FBI to determine the threat's legitimacy.

Officials asked students to stay where they were and those off campus to stay away while the threat was assessed.

College president Alison Byerly says no lockdown was initiated and students were free to leave buildings if they wished.