JERUSALEM, Israel -- In the wake of Monday's shootings at a Jewish school in Toulouse, France, Jewish institutions worldwide are increasing security.

NYPD Commissioner Raymond Kelly said although there were no specific threats against New York, "We know we're the top of the terrorist target list so we're concerned about the so-called copycat syndrome."

The shooter killed four people: Rabbi Jonathan Sandler, 30; his two sons, Arieh, 6, and Gabriel, 3; and 8-year-old Miriam Monsonego, the principal's daughter.

Eyewitnesses described a grisly scene.

"First of all they heard the shots and then parents shouting and crying. And then when he came out he saw the little children on the floor with blood around them.... and that's it," said Corinne Tordjman, mother of a pupil who was inside the Ozar Hatorah school at time of shooting.

Israeli President Shimon Peres asked "Where does it lead?"

"What is the sense of killing three children at the age of three, or five or six? What does it serve? Where does it lead? There is no good answer," Peres said.

French police said the same gun used at the school was also used to kill three French soldiers last week.

A massive manhunt is underway for the murderer.

French President Nicolas Sarkozy called the shootings a "frightening tragedy," and Israeli Prime Minister Benjamin Netanyahu didn't rule out a strong, murderous anti-Semitic motive.

The Israeli Foreign Ministry announced the victims will be buried in Israel.

Meanwhile, the murders have increased the sense of fear for many Jews feel living in France.

"I feel, I feel really that we [Jewish people] are not as comfortable in France as we were. We feel that the situation is turning, even most of the French," Jean-Paul Amoyelle, president of Ozar Hatorah, said.

"We are not anti-Semitic," he continued. "On the contrary, the Jews are here for many, many centuries. But there is a growing anti-Semitism."

Although the identity of the murderer is still unknown, the former head of Israel's counterterrorism bureau warned that a coalition of jihadist organizations have made a decision to attack Israeli and Jewish targets wherever they can.