A fire deemed suspicious destroyed a New York suburban synagogue of an anti-Zionist Jewish group heavily criticized for attending a conference last year where participants debated whether the Holocaust occurred.

No one was injured in Sunday night's fire in the town of Monsey. A senior Neturei Karta rabbi and his family, who lived on the top floor of the three-story structure, were not home.

"It may in the future be found to be accidental, but at this time we're treating it as a suspicious fire and we're investigating it as such," said Sgt. Daniel Hyman of the Ramapo Police Department, which provides services to Monsey, about 35 miles (55 kilometers) north of New York City.

The Neturei Karta has been the target of threats in the recent past because of their involvement in the anti-Zionism movement. The group has been widely criticized by other Jewish groups.

"Anybody who would like to reveal to the world their opposition to this political, national movement of Zionism is attacked," said Rabbi Yisroel Dovid Weiss of the Neturei Karta.

"A call of a fire in the kitchen area of the three-story structure came in to authorities at about 8:12 P.M. Sunday," Monsey Fire Chief Douglas Perry said.

He said that when firefighters arrived, one side of the house was engulfed in flames and power lines had come down. "It was too dangerous for any entry," he said, and the fire had to be fought from the outside.

"It's totaled," Perry said. "I would deem it dangerous to even go inside."

Weiss said that the group suspects arson because of previous threats.

"There's no question that the issue is to stifle the opposition to Zionism," he said.

In December, about five members of the group traveled to Tehran for a two-day conference convened to debate whether the Holocaust occurred. Some were photographed meeting with Iranian President Mahmoud Ahmadinejad, who has called the Holocaust a myth and has criticized the existence of Israel. Other Jewish groups were outraged.

Following the group's return from Iran, a large protest made up mostly of other Jews opposing their anti-Zionist views was held outside the Monsey synagogue. Neturei Karta refuses to recognize the existence or authority of Israel on the grounds that a sovereign Jewish state is contrary to Jewish law.

"The group does not dispute that the Holocaust occurred," Weiss said.