Palestinian police opened fire on a group of Israelis who sneaked in to pray at a Jewish holy site in the West Bank city of Nablus on Sunday, killing one and wounding four others, officials on both sides said.

Palestinian officials said that the worshipers, who were in three cars, had ignored warning shots after arriving in the early-morning hours for an unauthorized visit. The officials said that the policemen involved were held for questioning. The incident was under joint investigation by Israeli and Palestinian officials.

The shooting occurred near Joseph’s Tomb, a site inside Palestinian-controlled Nablus where Jewish settlers and strictly Orthodox Jews arrive periodically to pray under Israeli army escort, in coordination with the Palestinian police.

Sunday’s visit by members of the Breslov Hassidic sect was unauthorized, the army said. Palestinian officials told Israeli liaison officers that a policeman opened fire at the worshipers after “identifying suspicious movements,” according to an army statement.

A member of the Israeli group told the Israeli news Web site Ynet that they had removed a spike roadblock set up by the Palestinian police, sped toward the tomb as warning shots were fired in the air, and then came under fire when they returned to their vehicles.

Groups of Breslov Hassids and settlers regularly sneak in to Joseph’s Tomb to pray in addition to those who arrive on the visits coordinated by the Israeli army, according to organizers of the authorized pilgrimages.

Jibril al-Bakri, the Palestinian governor of Nablus, told Israel Radio that the police officers involved in the shooting had been detained. He said that warning shots were fired in the air and that if the policemen had indeed fired at the Israelis, it was by mistake.

The dead man was identified as Ben-Yosef Livnat, 25, a nephew of Limor Livnat, an Israeli cabinet minister from Prime Minister Binyamin Netanyahu’s Likud party. As the victim’s funeral headed for Jerusalem, attacks were reported on Palestinian property near Nablus, including the burning of a car, an attempt to torch a house, and stone-throwing at Palestinian vehicles.

Israeli Defense Minister Ehud Barak issued a statement calling the killing “a murder.”

“A coordination problem cannot justify such an incident and shooting at innocent people,” Barak said.