Published: Dec 13, 2010 8:59 PM EST
Updated: Dec 13, 2010 6:00 PM EST

FORT LAUDERDALE, Fla. (AP) — A Florida woman accused of making an e-mail threat that resulted in an hours-long lockdown of Broward County public schools has been ordered held without bail.

At a bond hearing Monday, a federal judge agreed with prosecutors that 48-year-old Ellisa Martinez did pose a flight risk and threat to the community.

Authorities say an e-mail from an address traced to Martinez was sent to a conservative talk show host in November, expressing plans to do "something big" around a government building in Broward, possibly a school.

A woman calling from Martinez's phone contacted WFTL radio station, claiming her husband was going to go to a school and start shooting.

Broward placed all 300 public schools on lockdown for several hours.