A Palestinian prisoner arrested by Israel in July died Tuesday after what the Israel Prison Authority said was a suicide attempt, a claim denied by the Palestinians.
The Palestinians named the man as Raed Abdel Salam al-Jaabari, 35, and called for an independent probe, describing the circumstances of his death as "mysterious."
Prisons spokeswoman Sivan Weizman told AFP the prisoner had hanged himself in the bathrooms at Eshel prison in the southern city of Beersheva.
She said a medical team had tried to revive him but that he was pronounced dead on arrival at Soroka hospital in the city.
"A prisoner hanged himself in the toilets," she told AFP, saying a team of paramedics, as well as prison officers, had tried to resuscitate him.
"They managed to revive him but, on the way to hospital, his heart apparently stopped working again and he was pronounced dead on arrival," she said.
She said he was serving time for assault and making threats but had no specific details.
The Palestinians blamed Israel, ruling out suicide as the cause of death, with the Ramallah-based Prisoners Club saying he had no known illness and calling for an impartial investigation.
Jaabari "died today in Eshel prison under mysterious circumstances," a statement said.
Prisoners' Club director Qadura Fares "cast doubt on the occupation's claims that the prisoner committed suicide and asked international organisations to investigate his death," it said.
Issa Qaraqaa, head of the Palestinian committee responsible for prisoners, said Jaabari had been arrested by Israel at the end of July for offences that were not immediately clear.
"Israel is responsible for his death," he told AFP.
"The Israelis say he tried to hang himself but it is not true. It is a lie," he said.
"This is a war crime."