An attack on a Sydney synagogue may have been fueled by anger over the Middle East conflict and the spiraling civilian death toll in Lebanon, a rabbi said Monday.

Rabbi Wernick, who cited religious reasons in declining to give his first name, and his young family were inside a house attached to a synagogue in suburban Parramatta when it was attacked Sunday evening.

Concrete blocks smashed the windows of two cars, and other projectiles were hurled at the synagogue roof. Shortly after the incident, witnesses told police they saw a group of about 10 Middle Eastern men laughing and running down a nearby street.

Werner said the conflict between Israel and Lebanon might have been a trigger for the attack.

"I don't see how people could link something that is going on the other side of the world to a small family synagogue," the 32-year-old Werner told reporters. "I feel a little sorry for them, that they think that is an appropriate action."

Police Acting Inspector Col. Green said police had stepped up their patrols of Jewish and Islamic sites following Israel's attacks on Lebanon.