An autopsy on the Palestinian teen who was kidnapped and found dead in the woods in Jerusalem last Wednesday revealed he was burned alive, officials said according to Reuters.

Mohammed Abu Khudair's "direct cause of death was burns as a result of fire and it's complications," Palestinian Attorney-General Mohammed Al-A'wewy said Friday. 

Officials believe the murder of Khudair, 16, was carried out by conservative Jewish vigilantes as a revenge attack for the slayings of three Israeli teenagers who were found dead in the West Bank two days before Khudair's death.

The teen was reportedly kidnapped in his Arab East Jerusalem neighborhood on Wednesday morning. His torched remains were found four hours later in a forest on the outskirts of the city.

At least 90 percent of the body's surface was covered in burns. Fire dust material that was found in Khudair's respiratory canal indicated "the boy had inhaled this material while he was burnt alive," Al-A'wewy said according to Reuters.

Forensic evidence collected from the remains will undergo more examinations for a complete medical report.

Clashes erupted in the West Bank between Palestinians and Israeli police after Khudair's death, with security forces using tear gas and stun grenades to quash the outraged crowds.

The increase in tensions between Palestinians and Israelis was fueled when three Israeli teenage boys were found dead in the West Bank city of Hebron last Monday. Israeli officials believe they were kidnapped by Hamas and murdered, a claim the Palestinian militant group refutes. 

Israeli Prime Minister Benjamin Netanyahu declared the nation was in mourning as the boys were laid to rest at their funeral on Tuesday. Khudair was reportedly kidnapped the next morning on his way to prayers.

Israeli Defense Forces have already stepped up airstrikes in Gaza and arrests of suspected Hamas members. Over 200 have been arrested so far.

Investigators have not confirmed if Khudair's murder was a hate crime carried out by far-right Jews, according to Reuters. Netanyahu called his death "loathsome" and ordered a police investigation.