An Israeli settler was shot dead by Palestinian policemen and four others were wounded after they slipped into Nablus without permission, officials said.
Palestinian officials said that dozens of armed ultra-Orthodox settlers got into Joseph's Tomb without coordinating with the Palestinian side, nor informing the Israeli military, Palestinian news agency Maan reported.
The militant settlers responded to the Palestinian officers' orders to leave because they lacked proper permission by pulling out their guns towards them.
Palestinian officials said that the first shots fired were into the air as a warning.
An Israeli military spokesman claimed that "Palestinian officials have notified ... (Israeli) officials that the civilians were shot by a Palestinian policeman who, after identifying suspicious movements, fired at their direction," as quoted in AFP.
Medics said one man remains in serious condition with a gunshot wound to the stomach. Another was in moderate condition with a bullet wound to his shoulder. Two others were lightly wounded.
Joseph's Tomb, which is in an area under full Palestinian control, is off-limits to Israelis outside of military organised and escorted trips.
A settler leader in the West Bank, Yaakov Haivri, claimed Palestinian security opened fire on the settlers as they were leaving the site, but confirmed that the worshipers failed to inform Israeli security of their visit, Maan reported.
The Palestinian Authority assured an investigation would be launched and that a committee has been formed for that purpose, excluding Israeli or US involvement.
The Israeli army said that military and civil administration officials would meet with Palestinian security representatives later Sunday to discuss the incident.