A Palestinian man, who was a driver near the rave, is thought to be held hostage in Gaza.

A young Palestinian man from East Jerusalem, Soheib Muhammad Abu Amar, is missing and believed to have been taken hostage by Hamas and ferried into Gaza, his family said.

Mr. Abu Amar, 22, is thought to be the only Palestinian who is not a citizen of Israel to be reported missing from the attacks on Oct. 7 and held by Hamas.

Mr. Abu Amar, a minibus driver, has an Israeli ID card but is not an Israeli citizen. On the night of Oct. 6, he picked up a group of partygoers in Jerusalem and took them to a rave festival near the Gaza border. He stayed overnight, intending to drive them back in the morning.

Hamas fighters and supporters broke through Israeli defenses early the next day, carrying out a series of attacks on Israeli soldiers and killing more than 1,000 civilians in Israel. They went on a deadly rampage in Israeli communities near the Gaza border and at the rave festival, taking scores of hostages back into Gaza.

“When the trouble began, he messaged us expressing concern,” said Mr. Abu Amar’s brother, Abd Al-Mughani Abu Amar, 37.“We told him to take care and assured him that there were police nearby to ensure his safety. At 9:22 a.m., he sent us a picture from near his bus.”

Ten minutes later, Hamas apparently had him.

At 9:32 a.m., Mr. Abu Amar called his brother-in-law, who said Mr. Abu Amar then handed the phone to a member of Hamas. The brother-in-law, who asked to remain anonymous to protect his family, asked who was on the phone. The man replied, “It’s Qassam.” The brother-in-law said: “I told him, ‘Leave him. He’s my brother. Let him go to his house; his mother is waiting for him. He is from Jerusalem, not from there,’ ” meaning Israel.

“He told me, ‘Listen, he is with me. I’m not leaving him, I’m keeping him with me,’” the brother-in-law said.

“No one from the government has provided any assistance or information, and we are anxiously waiting for someone to reach out to us,” Abd Al-Mughani Abu Amar said. “We have tried various avenues, including contacting the Red Crescent and the Red Cross, but they have been unable to provide any information.”

Soheib’s parents were in Saudi Arabia at the time of the attack, on a pilgrimage to Mecca, and have just returned. “My mom is devastated,” said Abd Al-Mughani Abu Amar. “My brother is a hard-working and honest person who just wants to earn a living and return home. He enjoys traveling and loves life.”