According to an account from the boy’s cousin, Mohammed Suleiman, Rayan had “run and fallen” Thursday after returning from school to find soldiers inside and outside his home.

He was taken to nearby Beit Jala hospital where he was declared dead, the cousin told AFP.

The Palestinian foreign ministry said Suleiman died after falling from a building “while being chased by Israeli occupation forces”.

A medical official who inspected the body told Reuters that it bore no sign of physical trauma and that the death appeared consistent with heart failure. The Palestinian Foreign Ministry condemned the incident as “an ugly crime” by Israel.

The Israeli army said its soldiers had searched the area after “a number of Palestinians hurled rocks toward civilians”.

But an “initial inquiry shows no connection between the searches conducted by the IDF (army) in the area and the tragic death of the child”, it said.

The US State Department said Thursday it supported “a thorough and immediate investigation into the circumstances” of the death.

The incident came a day after four Palestinians were killed in an Israeli army raid in the northern West Bank city of Jenin.

Clashes erupted with militants when the army entered Jenin to apprehend Abed Hazem, the brother of Raad Hazem who killed three Israelis in a shooting spree in Tel Aviv’s busy nightlife district in April.

Since March, Israel has launched hundreds of operations in the northern West Bank in pursuit of alleged militants, including in Jenin and nearby Nablus.

The raids have sparked clashes that have killed dozens of Palestinians, including fighters.

Israel has occupied the West Bank since the Six-Day War of 1967.

[With additional input from Reuters]