111Israeli and Palestinian pathologists have reached contradictory conclusions over the cause of death of a Palestinian cabinet member who collapsed after an apparent scuffle with Israeli troops in the West Bank

The Palestinian doctor said Ziad Abu Ain died as a result of a blow to his body, not of natural causes, but the Israeli doctor said the 55-year-old’s death was caused by the blockage of a coronary artery.

A senior Palestinian official earlier claimed that the post-mortem examination showed Mr Abu Ain died as a result of tear gas inhalation and beatings by Israeli troops.

Delays in getting Mr Abu Ain to hospital also contributed to his death, said Hussein Sheikh, the Palestinian minister of civil affairs.

Images from the scene at a village near Ramallah showed an Israeli officer grabbing Mr Abu Ain by the throat before he collapsed, which quickly stirred Palestinian anger at a time of badly strained relations with Israel.

The Israeli military said later that paramilitary border police had clashed with 60-100 rock-throwing Palestinians in the West bank city of Hebron.

Palestinian president Mahmoud Abbas called Mr Abu Ain the victim of a “clear crime” and a “barbaric act”.

He decreed three days of mourning for the minister, whose portfolio included organising protests against Israeli settlements and the West Bank separation barrier.

Calls grew for Mr Abbas to suspend security co-ordination with Israel – a policy that has become the cornerstone of relations between Israel and the Palestinian Authority in the absence of peace talks.

Mr Abbas met officials from his Fatah movement and the Palestine Liberation Organisation to consider a response and said all options were open.

In the session, Mr Abbas held up a photo of the Israeli officer grabbing Mr Abu Ain’s throat. Palestinians circulated the photo on social media under the hashtag #ICantBreathe – drawing a link to the death of an unarmed black man after he was placed into a chokehold by a white police officer in New York.

Israeli defence minister Moshe Yaalon said the military was ready to investigate the incident with Palestinian officials.

The US called for a “swift, fair and transparent” inquiry into the incident. “At this difficult time, we continue to call on both sides to work to lower tensions and prevent an escalation of violence,” State Department spokeswoman Jen Psaki said.

UN head Ban Ki-moon and EU foreign policy chief Federica Mogherini urged restraint, amid fears the minister’s death could lead to a further deterioration in Israeli-Palestinian relations, already at a low point after failed US-led peace efforts.

Mr Ban said he was “deeply saddened” by the death, while Ms Mogherini said “reports of excessive use of force by Israeli security forces are extremely worrying”.

The Israeli military said it was sending two battalions of soldiers and two companies of paramilitary border police to the West Bank as reinforcements.

The day’s events began around mid-morning when several dozen Palestinians, including Mr Abu Ain, marched from the West Bank village of Turmus Aya toward an unauthorisedIsraeli settlement outpost, Adei-Ad.

They planned to plant olive tree saplings on land belonging to one of the villagers, who has repeatedly been barred from reaching his property by Israeli troops citing concern about frictions with the settlers, participants said.

Several dozen soldiers and members of the paramilitary border police blocked the marchers, firing tear gas and stun grenades, according to Palestinian witnesses and members of Yesh Din, an Israeli rights group that joined the protest.

Eventually, marchers and troops faced each other, scuffling and shouting.

Mr Abu Ain, who was at the front of the group, told reporters: “We came to our Palestinian land to plant some olive trees and they attacked us immediately. No one threw a stone or attacked them, but this terrorist army is attacking us.”

At one point a border policeman grabbed the Palestinian minister by the throat and pushed him, according to an Associated Press photographer. Other witnesses said a soldier pushed a rifle butt into Mr Abu Ain’s chest.

Several minutes later, a pale-faced Mr Abu Ain was seen sitting on the ground, then leaning back against a large rock, his right hand clutching his chest. A bystander tried to help him, patting his back and getting him to sit up, before he slumped backwards.

An aide, Abu Sassaka, said an Israeli soldier administered first aid to Mr Abu Ain before protesters carried him away. An ambulance took him to Ramallah Hospital and he died en route.

The Israeli daily Haaretz quoted relatives of Mr Abu Ain as saying he suffered from diabetes and high blood pressure.

The Israeli military said that about 200 “rioters” had gathered in Turmus Aya and that troops prevented them from reaching Adei-Ad, using “riot dispersal means”. That typically means tear gas and stun grenades.

Mr Abu Ain’s funeral procession began at Mr Abbas’ Ramallah headquarters.

Several thousand mourners, including Mr Abbas, gathered in the walled compound and said prayers over the minister’s coffin, which was draped in a Palestinian flag.

From there, the procession headed toward a nearby cemetery, with some in the crowd shooting in the air.

Anticipating Palestinian protests over the death, the Israeli military has sent troop reinforcements to the West Bank.

Earlier today, several dozen Palestinian stone-throwers clashed with Israeli troops in the West Bank city of Hebron.