A gunman has opened fire on a Jewish school in the French city of Toulouse, killing three children and an adult, police say.
At least two people were also injured in the attack outside the Ozar Hatorah school in the north-east of the city.
Police are hunting for the gunman, who witnesses said was riding a black scooter.
The attack comes days after three soldiers were shot dead by a man on a scooter in the same part of France.
President Nicolas Sarkozy, his education minister and interior minister are travelling to Toulouse, in south-west France.
The grand rabbi of France, Gilles Bernheim, who is also on his way to the city, said he was "horrified" and "stunned" by what had happened.
Israel also said it was horrified, adding that it trusted the French authorities "to shed full light on this tragedy and bring the perpetrators to justice".
Monday's attack happened as children and their parents were arriving at the Ozar Hatorah school, in the Joliment area of the city, for the start of the school day.
The French network BFMTV said the dead included a school teacher, his six-year-old daughter and a 17-year-old school boy.
There is no information yet on the third child killed.
Local residents have immediately linked the shootings with last week's attacks on the soldiers.
A 30-year-old paratrooper out of uniform was gunned down in a residential area of Toulouse just over a week ago, while two soldiers were killed and a third wounded as they used a cashpoint in the town of Montauban, some 29 miles (46km) away, on Thursday.
All the soldiers were of North African origin.
Some 60 police officers, including anti-terrorist specialists, had been drafted in to help investigate those attacks.
They have been looking for a gunman who was targeting soldiers, the BBC's Christian Fraser in Paris says.
But if the latest attack does prove to be linked, then it suggests the pattern has changed and, if so, police are looking for a dangerous serial killer, our correspondent adds.