Two more colleges had to close today as a result of the continuing wave of bomb scares and other copycat threats that have hit American higher education since last week’s shooting rampage at Virginia Tech.

Delta State University closed its campus this afternoon after receiving several bomb threats that, one official said, could not be ignored in the wake of the Virginia Tech killings. According to The Clarion-Ledger, a newspaper in Jackson, Miss., it was unclear if the university, located in the northwestern part of the state, would reopen on Wednesday. No bombs have yet been found.

Yakima Valley Community College, in Washington, closed today after receiving undisclosed “threats of harm to people on campus,” according to a local police officer quoted in the Yakima Herald-Republic.

“After Virginia Tech, you don’t want to be the one to under-react,” the officer, Capt. Greg Copeland, told the newspaper. “You would be crucified if something were to happen.” —Andrew Mytelka