JERUSALEM (Reuters) – Police in Israel said an Arab Israeli on Wednesday rammed his car into a group of policemen in the southern Negev region, killing one before being shot dead, though a rights activist who was present disputed it was an attack.

Police said the violence sparked a riot in the village of Umm al-Hiran, where an operation was underway to demolish Bedouin dwellings deemed by a court as having been built illegally on state-owned land.

Police spokeswoman Merav Lapidot said the suspect was a local teacher who “surged towards the forces intending to kill” and that riots erupted after he was shot.

But human rights activist Michal Haramati, who had come to Umm al-Hiran to observe the demolitions, said she witnessed the event and that the driver was not heading towards police when he was shot.

“Suddenly the car started to go down the hill, without control, absolutely,” she told Reuters in English. “The driver was obviously dead by the time that he lost control this way. That’s when he hit the cops.”

Most of Israel’s Bedouin, who predominate in the desert area that accounts for two-thirds of Israel’s territory, are nomadic tribes which have wandered across the Middle East from Biblical times. Arab citizens make up about 20 percent of Israel’s population of eight million, and 200,000 of them are Bedouin.

Bedouin leaders in Negev say Israel has long discriminated against their communities, denying them public funds and services. Half of Israeli Bedouin population live in towns and villages recognized as formal communities by the government. Others live rough, in tents and shacks on patches of desert.

Israeli forces have been particularly wary of car ramming attacks since a wave of Palestinian street assaults began in October 2015.

On Jan. 8, four Israeli soldiers were killed in Jerusalem by a Palestinian who drove his truck into them.

In all, 37 Israelis and two visiting Americans have been killed in the past 15 months, while at least 232 Palestinians have been killed in violence in Israel, the occupied West Bank and the Gaza Strip in the same period. Israel says that at least 158 of them were assailants while others died during clashes and protests.

(Reporting by Maayan Lubell; Editing by Jeffrey Heller and Raissa Kasolowsky)