— What happens next on the streets of East Jerusalem and the West Bank may rest on one question: What killed a prominent Palestinian cabinet minister during a clash Wednesday with Israeli soldiers?

The already tattered relationship between the Israeli government and Palestinians can, in fact, get much worse. The death of Ziad Abu Ein — a senior leader, a former prisoner, popular on the streets and known to young people — led Palestinian officials to threaten again to curtail security coordination in the West Bank between their forces and the Israeli military. Israel fears such a move would unleash chaos for all.

As the flag-draped coffin carrying Abu Ein was carried from the Palestinian Authority headquarters in Ramallah in a massive funerary procession Thursday, Israeli and Palestinian authorities tussled over the precise cause of his death. At issue was whether the chain-smoking, hard-driving Abu Ein died of cardiac arrest brought on by the stress of a confrontation with Israeli troops — or had been killed by a blow struck by an Israeli soldier and a choking blast of tear gas.

It was the latest example of a long-standing theme whereby the two sides rarely agree on the same set of facts.

Palestinian Civil Affairs Minister Hussein al-Sheikh told Voice of Palestine radio that a late-night autopsy found that Abu Ein died from “being struck, inhaling tear gas and a delay in providing medical attention.” At an emergency meeting Wednesday, Palestinian Authority President Mahmoud Abbas waved a photograph of Abu Ein being clutched by the throat by an Israeli soldier.

Members of the Palestinian national security forces carry the body of Palestinian Cabinet member Ziad Abu Ain during his funeral in the West Bank city of Ramallah, Thursday. (Majdi Mohammed/AP)

Israel’s Health Ministry, however, announced Thursday that the same autopsy showed that Abu Ein’s death was “caused by a blockage of the coronary artery due to hemorrhaging underneath a layer of atherosclerotic plaque.” The forensic report concluded, “The poor condition of the deceased’s heart caused him to be more sensitive to stress.”

The autopsy was attended by Israeli, Palestinian and Jordanian pathologists in an attempt to avoid this very fight.

Saber Aloul, the Palestinian pathologist who attended the autopsy, told the Associated Press that the “cause of death was a blow, and not natural causes.”

Chen Kugel, chief of the Israeli National Institute for Forensic Medicine, told reporters there was no real difference in the versions — that a stressful event led to a heart attack.

The Israeli news Web site Ynet quoted Kugel, who took part in the autopsy, as saying that the disagreement with the Palestinians stemmed also from damage on the victim’s front teeth, tongue and windpipe, which could have been the result of resuscitation attempts or an attack.

Speaking in Jerusalem, Israeli President Reuven Rivlin said that the country “is committed to carry out a careful examination into the events which led up to Abu Ein’s death.”

After Abu Ein’s funeral, Palestinians threw rocks and bottles at Israeli soldiers near the Jewish settlement of Psagot, according to the Palestinian news agency Maan. The Israeli troops responded with rubber bullets.

Israeli Foreign Minister Avigdor Lieberman charged that Palestinian leaders, including Abbas, were using Abu Ein’s death to incite their constituents. In a statement, Israel’s top diplomat called the Palestinian assertions about the use of excessive force “contemptible” and “baseless.”

The dispute over the cause of death — and sensational videos taken at the scene that show an Israeli Border Patrol officer holding Abu Ein by the throat — could quickly become a flash point for further Palestinian protests and political fallout.

Tensions in the region are already heightened after months of Palestinian terrorist attacks, a 50-day war in the Gaza Strip and recent clashes over a contested holy site in Jerusalem.

Abu Ein, 55, was an immensely popular Palestinian government minister who directed the agency tasked with opposing Israeli settlements and the barrier separating Israel and the West Bank. Until recently, he had served as a spokesman for Palestinians serving long sentences in Israeli prisons for terror attacks and other activities.

Thousands of mourners crowded into the official government compound in the West Bank town of Ramallah to attend Abu Ein’s funeral.

“Everyone knows Abu Ein,” said Yazmin Israyah, 19, a media student.

She said she hoped that his death would not just be another sad day for Palestinians, “but a spark.” Israyah said that she would support whatever Abbas did but that if it were up to her, she would end all cooperation with the Israelis.

Palestinian National Council member Tayseer Naserallah, who spent several years in an Israeli prison with Abu Ein, said that his death could represent a turning point in the rise of popular resistance among Palestinians.

“We have wasted a lot of time trying to make peace with the Israelis,” Naserallah said.

“There is no value in an Israeli apology,” he said. “There is bloodshed every day.”

Abu Ein was a member of Fatah’s Revolutionary Council, also known as the Abu Nidal Organization, which carried out terror attacks against Israelis in the 1980s. He was given a life sentence in Israel in 1982 after being extradited from the United States over the killing of two Israelis in Tiberias in 1979. He was released in a prisoner swap in 1985.

Abu Ein spent a year in detention in 2002 without being charged when he was a leader of the second Palestinian uprising, or intifada, in which thousands of Israelis and Palestinians died and Palestinian suicide bombings against civilian targets were commonplace.

Eglash reported from Jerusalem. Sufian Taha in Ramallah contributed to this report.