LOS ANGELES, Dec. 15 -- Los Angeles Unified School District (LAUSD) will reopen more than 900 of its campuses Wednesday after an email threat appeared to be a hoax.

Responding to a threat emailed to school board members and campuses, all LAUSD campuses were closed for Tuesday, followed by an exhaustive search of the schools.

After more than 1,500 school sites were searched in Los Angeles, the threat was found to be "not credible."

Officials said the threat made reference to bombs, weapons and other destructive devices that had allegedly been planted on campuses throughout the district.

LAUSD Superintendent Ramon Cortines said he made the unprecedented decision to close all school campuses out of an abundance of caution, saying that "based on past circumstances, I could not take the chance."

"I am not taking the chance of bringing children any place, into any part of the building, until I know it is safe."

A similar threat was also received by schools in New York City, but officials soon concluded that the threat was not credible and allowed schools to open as normal.

New York Police Commissioner Bill Bratton, former chief of the Los Angeles Police Department, criticized LAUSD's decision to shutter all campuses as "significant overreaction."

A U.S. Congressman said the threat appears to be a hoax. "While we continue to gather information about the threat made against the Los Angeles and New York school departments, the preliminary assessment is that it was a hoax or something designed to disrupt school districts in large cities," said Rep. Adam Schiff, also ranking member of the House Permanent Select Committee on Intelligence.

LAUSD officials would not provide specifics of the threat, which was initially reported by police to have come via telephone, but was later revealed to have come in via email, apparently either from or routed through Frankfurt, Germany.

LAUSD is the second-largest school district in the United States, which has more than 700,000 students.