Israeli police said Tuesday they are searching for a U.S. religious student who disappeared while on a hike in a forest outside Jerusalem last week.

Twenty-three-year-old Aharon Sofer of Lakewood, New Jersey, was last seen Friday, said police spokesman Micky Rosenfeld.

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

Rosenfeld said that police have launched an extensive search for Sofer, who is an ultra-Orthodox student at a yeshiva — a Jewish religious school named for its founder, Rabbi Tzvi Kaplan. Sofer's parents have flown to Israel.

Rosenfeld said Sofer was with a friend when he disappeared during a hike in the Jerusalem Forest. He said authorities have interviewed the friend and "are looking in all different directions" for Sofer.

U.S. Rep. Chris Smith and other New Jersey politicians attended a news conference Tuesday to draw attention to the missing student.

"I want the community to know that I believe no stone is being unturned," said Smith, a Republican who has written to U.S. Secretary of State John Kerry asking for aid in the search.

At Tuesday's gathering in Lakewood, the missing man's brother, Yaahkov Sofer, pleaded, "Please bring him back." He declined to speak further about his brother, who is one of 10 children in the family where the parents are a rabbi and a school office worker.

In Lakewood, there are growing worries about Sofer.

"Is he abducted?" asked Rabbi Yisroel Serebrowski, who leads a congregation in Cherry Hill and says he is a friend of the missing student's parents. "Is he being tortured?"

"This is a real person who has real parents who are suffering," Serebrowski said.

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.

On Tuesday, Israel and Hamas announced that they had agreed to an open-ended cease-fire in the war that stemmed from the abduction and killing of three Israeli teens in the West Bank by Hamas operatives.

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