Israeli police are searching for a young New Jersey religious student who disappeared during a hike in a forest outside Jerusalem last week, and the man's relatives fear the worst.

Aaron Sofer, 23, of Lakewood, N.J., has been missing since Friday, when he went on a hike with a friend in the Jerusalem Forest, police spokesman Micky Rosenfeld said.

Rosenfeld said police have launched an extensive search for Sofer, an ultra-Orthodox student at a yeshiva, a Jewish religious school. Sofer's parents have flown to Israel.

Shlomo Sofer, Aaron's cousin, criticized the search response and called on the Israeli military to get involved. He told FoxNews.com roughly 500 people took part in searches of the Beit Zayit area of the woods on Tuesday.

[pullquote]

"What happened here is unknown, but it's pretty clear that he's not in the forest," Sofer, 40, told FoxNews.com. "Something is not quite right. We have every reason to assume that something hostile happened. Bottom line: Where is he?"

Sofer said investigators have found "no trace" of Aaron, who he described as a friendly and respectful young man who had no recent mental or physical issues.

"This is a young, American student who came to Israel to spend a year or two here," he said. "And there's no reason to assume he has committed suicide or has done anything silly or immature. We feel they should be taking further measures in terms of investigating a possible abduction."

Shlomo Sofer also called on the U.S. State Department to get involved in the case.

"This is an American citizen and the U.S. government has full responsibility to bring him home safely," he said. "If Americans don't wake up now, I don't know when they're going to wake up."

A State Department spokesperson told FoxNews.com that they were aware of the reports but couldn't offer further information due to privacy considerations.

"One of the Department of State’s highest priorities is the protection of U.S. citizens overseas," the spokesperson said. "When a U.S. citizen is missing, we work closely with local authorities and cooperate fully in their search efforts.”

Some New Jersey politicians on Monday called for more help from both the U.S. and Israeli governments in the search for Sofer. Rep. Chris Smith, R-N.J., and other local officials were planning a news conference for Tuesday in Lakewood to seek help in finding the student.

Rosenfeld said police were pursuing all avenues in their investigation, including the possibility that Sofer may have fallen victim to an attack by Palestinian militants.

The crisis between Israelis and Palestinians has spiked in recent weeks with the war between Israel and Hamas in the Gaza Strip, which erupted on July 8.

That war stemmed from the abduction and killing of three Israeli teens in the West Bank by Hamas operatives in June, which triggered a massive Israeli arrest campaign in the West Bank, followed by an increase in rocket fire from Gaza.

In an apparent revenge attack, right-wing Israeli Jews kidnapped and burned to death a young Palestinian boy near Jerusalem in early July.

The Associated Press contributed to this report.