Ramallah - Hundreds of people gathered here on Sunday for the funeral of Mohammed Tarifi, the fourth Palestinian to die amidst a widening 10-day-old Israeli offensive in the occupied West Bank.
The operation started last week after three Israeli settlers disappeared while hitchhiking home from their seminary in an illegal settlement near Hebron.
More than 350 Palestinians have been arrested and some 1,300 homes raided as Israeli troops hunt for the missing settlers.
On Saturday night the army moved into downtown Ramallah, where Tarifi was found dead on a rooftop. Hospital sources said an autopsy confirmed that he was killed by a bullet from an M-16 rifle, which is used by Israel but not by Palestinian security forces.
A second man was shot dead by border police near Nablus overnight.
The Palestinian Authority (PA) has worked closely with Israel to find the young settlers, with Israeli officers speaking highly of their efforts.
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On Sunday the PA even returned an Israeli surveillance drone that crashed in Hebron. On the street, though, these close ties are a source of increasing tension.
Angry Palestinians attacked a police station in Ramallah overnight after Israeli troops withdrew. Mourners in Tarifi's funeral procession chanted slogans against cooperation.
"The [Palestinian] Authority collaborates with the Israelis, and this is what we get, more martyrs," said Fares Abu Issa, 68, sitting at the cemetery after Tarifi was buried.
"We need national unity now, but on the contrary, the leadership is not standing with the people."
Husam Zumlot, a senior member of the Palestine Liberation Organisation, hinted at the growing frustration in an interview with Al Jazeera, saying that "security cooperation requires Israeli cooperation."
He accused Israeli Prime Minister Benjamin Netanyahu of using the suspected kidnappings as an excuse to weaken the entire Palestinian national movement.
"Netanyahu is doing what he has been wanting to do all these months and years," Zumlot said, "to finish off any possibility for a solution."
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Israel has blamed Hamas for the disappearances, and Netanyahu said on Sunday that there is "unequivocal proof" of the group's involvement, though none has been offered publicly.
The incident has threatened to unravel a reconciliation pact agreed by Hamas and Fatah in April.
Justice Minister Tzipi Livni, the chief Israeli negotiator with the Palestinians, told Channel 2 on Saturday night that she worried recent events could also undermine the government in Ramallah.
"[Israel] needs to hit Hamas hard, and it needs to remember who its partner in the negotiations is," Livni said. "Our cooperation with the PA is in accordance with Israel's interests."
Mahmoud Abbas, the Palestinian Authority president, has condemned the suspected kidnappings but also described the military offensive as collective punishment.
Back at the cemetery, as mourners shoveled dirt onto Tarifi's grave, gunfire sounded out from the illegal settlement of Psagot perched on a hill above, injuring one person. It was unclear whether the shots came from soldiers or settlers.
The crowds scurried away, leaving Tarifi's body buried next to that of his brother Eyad, who was killed by Israeli troops in 1996.