The FBI said evidence found near the scene of an explosion Thursday next to a Santa Monica synagogue was linked to an “extremely dangerous” suspect now being sought in the blast.

The explosion was first believed to be an accident. But “technicians and detectives conducted further forensic analysis at the scene and, after unearthing much of the large portion of the cement found, uncovered materials indicating that the device appeared to have been deliberately constructed,” the FBI said in a statement. “Investigation has determined that items found in and around the mechanism are linked to an individual by the name of Ron Hirsch, identified as a transient.”

Law enforcement sources told The Times that gun powder was among the items found in the explosive device. Officials have not said exactly how they linked the evidence inside the explosive device to the suspect.

Hirsch, 60, also known as Israel Fisher, is thought to be behind Thursday morning’s blast outside Chabad House on 17th Street between Broadway Street and Santa Monica Boulevard. Police described Hirsch as a transient.

“Hirsch should be considered extremely dangerous,” said a police bulletin sent to other law enforcement agencies.

He is described as white, 5 feet, 7 inches tall, 207 pounds, with brown hair and green eyes.

The bulletin said Hirsch was known to frequent synagogues and Jewish community centers in search of charity, among them Congregation Bais Yehuda on North La Brea Avenue in Los Angeles.

The blast sent a 300-pound metal pipe encased in concrete hurtling through the air and crashing through the roof of a home next door to Chabad House. Originally authorities had said they believed the explosion was a freak industrial accident.

But on Friday, bomb technicians and detectives scouring the scene discovered evidence that the blast was caused by an explosive device, police said. Items found nearby were linked to Hirsch, who was being sought on state charges of possession of a destructive device and other charges.

The motive for the attack was unknown, police said. Joining local authorities in investigating the case were the FBI and the U.S. Bureau of Alcohol, Tobacco and Firearms.

On Friday afternoon, the Anti-Defamation League issued a security alert to synagogues and other Jewish organizations in the Los Angeles area.

“ADL has no information regarding a specific threat against any Jewish institution,” the league announced in the alert. “However, community members should be extra vigilant.”

Amanda Susskind, the league’s Los Angeles regional director, said in an interview that the alert was “not intended to create panic or a drama,” but rather to keep people on the outlook for a man who seems to be disturbed.

She also said there was no indication that the suspect was part of a terrorist plot.

(Source: LA Times)