Thousands of people, including from Iraq's Yazidi and Turkmen minorities, are in dire need of help after fleeing the jihadist takeover of Sinjar, rights activists said Monday.
According to the UN, up to 200,000 people fled the northern town when Islamic State fighters moved in and Kurdish peshmerga troops retreated on Sunday.
Many were Yazidis, a small community that follows a 4,000-year-old faith and has been repeatedly targeted by jihadists who call them "devil-worshippers" because of their unique beliefs and practises.
Sinjar was their main hub in Iraq but the town of 300,000 fell to the Islamic state group which took the main northern city of Mosul on June 10 and this weekend secured much of its hinterland.
"What Daash has done against the Yazidis in Sinjar is ethnic cleansing," said Khodhr Domli, a Yazidi rights activist based in the Kurdish city of Dohuk.
Daash is the Islamic State's former Arabic acronym.
"There are still thousands of people heading to Dohuk but thousands are also trapped in the Sinjar mountains," he told AFP.
"There are old people among them, children. They have no food nor water, some have died already."
"We last had contact with them last night (Sunday) but this morning we have not been able to make contact," Domli said. "They face a double threat: nature and Daash."
Sinjar was also home to hundreds of families from the Turkmen Shiite minority who had fled nearby the city of Tal Afar in the early days of the jihadist offensive nearly two months ago.
Ali al-Bayati, a Turkmen rights activist, said he was receiving very alarming reports about the people who were forced back on the road on Sunday.
"Out of the 500 Turkmen Shiite families who had to flee, about 100 or more were able to reach a cement factory located about 15 kilometres outside Sinjar," he said.
"They are still there and have nothing. They need help," he said.
Bayati said that a larger group was met on their flight by IS fighters, who executed many of the men.
"The terrorists took the women as slaves and are now holding a large group at Tal Afar airport."
The UN on Sunday expressed "grave concerns for the physical safety of these civilians" who fled Sinjar.
There was no information immediately available on the fate of the displaced from Iraq's federal government or the autonomous Kurdish government.