A gunman shot and wounded two men in the parking garage of a San Fernando Valley synagogue early Thursday, and Jewish schools and temples were put on alert in case it was not an isolated attack.

Two men in their 40s were shot in the legs near the Adat Yeshurun Valley Sephardic Orthodox synagogue in North Hollywood, Deputy Police Chief Michel Moore said. The men, both members of the synagogue, had arrived in separate cars for the morning service shortly before 6:30 a.m. when the gunman approached one and, without speaking, shot him and the other man, Moore said. The men were hospitalized in good condition.

Police later detained and handcuffed a man not far from the synagogue. The youth, believed to be about 17 years old, matched the “very loose” description of the attacker, who was described as a black man wearing a hoodie, Moore said.

Officers cordoned off the area and continued to search for a possible suspect, Moore said.

There were no security guards in the parking garage but investigators will look at the synagogue’s security videos, he said.

There was no immediate word on a motive.

“We have to assume, because it was a synagogue, it was a service [and] that there was no other apparent motive, we’re looking at it as a hate crime,” Lt. John Romero said.

The FBI also responded to the scene, and police alerted nearby Jewish schools and temples and put extra patrols in place. There are several synagogues in the area.

“We are being vigilant for any follow-ups that may occur,” Moore said.

The Anti-Defamation League expressed “deep concern” over the attack, in a statement released Thursday.

“While we have not confirmed the motive behind this horrendous act, we obviously take a shooting at a synagogue very seriously and ask for the community to contact LAPD or ADL with any information,” said Amanda Susskind, Regional Director of the ADL.

“We commend the Los Angeles Police Department for immediately committing resources to vigorously investigate this crime and for their continuing commitment to the protection of all religious institutions,” she added.

The statement said that the organization was working with the LAPD, as well as the L.A. mayor’s office.

Shayan Yaghoubi, 13, was walking with his mother to the synagogue’s adjoining school but wasn’t allowed to cross the police line.

“The cops told us we can’t go,” he said. “I feel very bad because this is my favorite school … I have a lot of friends over there. I hope everyone is OK. There’s never been a problem with fighting.”

The attack occurred 10 miles from Jewish community center where white supremacist Buford Furrow wounded three children, a teenager and an adult, in 1999. Furrow later killed a Filipino letter carrier on another street.

Furrow, who is serving a life sentence without chance of parole, told the Daily News of Los Angeles in a letter last month that he had renounced his racist views and regretted the pain he had caused.