Two people were injured in a school shooting which sparked a terrorist attack warning in France.
An armed teenager has been arrested following the incident.
The French government launched the terrorist attack warning following a shooting at a high school in the southern town of Grasse.
As part of the alert, police urged residents to stay indoors.
Two people were wounded in the shooting but all students are safe, a government minister said.
BFM TV reports that the attacker was targeting the school's headmaster at Tocqueville high school.
Meanwhile, a letter exploded when it was opened at the offices in central Paris of the International Monetary Fund (IMF) on earlier today and one person was injured, police sources said.
One person was arrested at the scene.
Paris police department said on Twitter an operation was ongoing at the offices of the IMF and World Bank after a person was hurt following the apparent explosion of a suspect package.
"An envelope exploded after it was opened and one person was slightly injured in the offices of the IMF," one police source told Reuters.
The incident, just six weeks before a presidential election, comes as a militant Greek group Conspiracy of Fire Cells claimed responsibility for a parcel bomb mailed to German Finance Minister Wolfgang Schaeuble on Wednesday.
Staff from the IMF office were evacuated and armed military officers and police guarded the area, in a chic district of western Paris.
The World Bank office in France is in the same compound.
No other damage was reported in the explosion, according to a police official.
It is unclear who sent the explosive.
Thursday's incident came a day after a package arrived at the German finance ministry containing low-grade explosives, like those used in firecrackers.
Mail room employees at the ministry quickly identified the package as suspicious and called in explosives experts, who destroyed it with a controlled explosion.
France remains in a state of emergency after a string of deadly Islamic extremist attacks over the past two years.