Prosecutor Philippe Vanier said the youths, who were arrested after one turned himself in on Monday and implicated the others, had admitted to spitting on the Star of David on the tombs and giving straight-arm Nazi salutes.
They denied anti-Semitic motives but Vanier disputed that, saying: "In spite of their denials, the anti-Semitic connotation and motivation of their behaviour appear clearly."
Under French law, suspects put under judicial investigation by a magistrate on the advice of a prosecutor are likely to go to trial. A prosecutor's finding of anti-Semitic motives would add weight to the accusations against them.
Vanier said the youths, aged 15 to 17, had desecrated the tombs at the Jewish cemetery of Sarre-Union near the German border and damaged a monument erected in memory of victims of the Holocaust.
He has asked for them to be sent to an education centre and placed under formal investigation for desecrating tombs for religious reasons and damaging public assets.
They could get up to seven years in prison, or half that amount if the court takes into account the fact that they are minors. Their identity was not revealed.
The desecrations last Thursday shocked France, where four Jews were killed last month in an attack on a Paris kosher grocery linked to the assault on the satirical weekly Charlie Hebdo that ended with 12 dead.
President Francois Hollande visited the Sarre-Union cemetery with Jewish leaders on Tuesday and said the profanations were "the expression of the evils gnawing away at our republic".
In another attack, dozens of tombs at a Christian cemetery in northern France were damaged late on Tuesday, Interior Minister Bernard Cazeneuve said.
