A bomb seriously injured an Israeli diplomat and four other people when it blew up the envoy's car today on a busy Paris street, French police said.

The bombing, on the eve of the Jewish Rosh Hashana holiday, was the 10th anti-Semitic attack in Paris since July.

An Israeli diplomatic spokesman said the injured in the car were Amos Man-El, an official of the Israeli Embassy's military purchasing mission, which is located near the site of the explosion, and two visiting relatives, his cousin Zoltan Mandel, and Mandel's wife, Veronica, Reuter reported. United Press International said Man-El's wife, Juliana, was also in the car.

The blast shattered windows in a nearby high school, and about 40 students suffered cuts from the flying glass, police said.

Two teen-agers walking past the car as it exploded and the two Mandels were the most seriously injured, but the nature of their injuries was not immediately made known by police. The Israeli spokesman said Man-El apparently was not in danger.

A caller to a Paris news agency claimed responsibility for the bombing in the name of the Revolutionary Lebanese Army Faction.

The same organization claimed responsibility for three other terrorist attacks here, the April 3 murder of Israeli diplomat Yacov Barsimantov, the murder of U.S. military attache Lt. Col. Charles Ray Jan. 18 and the unsuccessful attack against U.S. Charge d'Affaires Christian Chapman Nov. 12, 1981.

The explosion occurred on Rue Cardinet in Paris' 17th District a few blocks east of the Arc de Triomphe, and across the street from the Lycee Carnot, where about 500 high school students were in classes. The Israeli Embassy's military purchasing annex is around the corner on the Boulevard Malesherbes.

Six months ago, the Israeli military annex was sprayed by machine-gun fire.

According to the French Jewish organization Renouveau Juif, the bomb was planted in the saddlebags of a motor bike near the parked car and exploded as the driver started the car.

The blast hurled the car several feet into the air, and it landed in the middle of the street, witnesses said.

The diplomat, according to witnesses, pulled himself out of the car as it burst into flames, then collapsed in the middle of the street. Firemen worked for a half hour before freeing the other two passengers, who were sitting in the right front and rear of the car.

French Premier Pierre Mauroy who was attending a meeting on terrorism, said that "unfortunately, these attacks are not a new phenomenon . . . . This type of terrorism is not the product of French society itself . . . but a kind of imported terrorism linked to the Middle East crisis."

Israeli Ambassador Meir Rosenne met with Mauroy immediately after the bombing. In a radio interview Rosenne blamed the Palestine Liberation Organization for the attack, citing what he said was a statement by a PLO official that "they will make the life of any Israeli impossible wherever he is."

"The only way of preventing further attacks is by refusing to allow terrorist organizations to settle on a country's territory," he said.