Miami: Over 300 schools in Florida`s second most-populous county were put on lockdown on Wednesday after a woman told a radio station her husband was going to "start shooting at schools”.
By the afternoon, the lockdown was lifted but all after-school activities were suspended for the day.
Students had been kept at all of Broward County`s schools for the day and police in the Fort Lauderdale suburb of Pembroke Pines were investigating the case, said an agent with the county sheriff`s department.
The county is located just north of Miami.
Shortly after 8:30 am (1330 GMT), an e-mail was also sent to the radio station warning that "something big was going to happen at government buildings in Broward County, maybe at a post office or a school”.
Captain Dan Rakofsky of the Pembroke Pines Police Department said it was deemed a "credible threat" and as a precaution, Deputy City Attorney Julie Klahr ordered the lockdown of 231 traditional schools and 69 charter schools.
"We are trying to trace the origin of the phone call and the e-mail but we have yet been unsuccessful," Rakofsky said.
"We are working with the FBI and numerous state agencies to investigate some names we believe may be associated with this but because they are very common names we are unsure if they are pseudonyms or if they are actual people."