French police arrested a woman in the northern Dunkirk hospital on Wednesday after she threatened to blow up a bomb at the scene and caused panic.
Police said in a statement that the woman launched her threat after entering the emergency unit in the hospital.
The hospital staff told the police, who had closed the area in turn, and sent a team to dismantle the explosives.
"Women are under police control," a statement said.
A local newspaper reported that the woman threatened to detonate a bomb, and pictures showed police cars on the Internet and the area was closed.
Police said a judicial inquiry would reveal the circumstances surrounding the threat, while sources suggested that women were likely to have psychological problems.
