JERUSALEM An autopsy of the Palestinian teenager who was snatched from an East Jerusalem street and slain Wednesday found soot in his lungs that suggests he was burned alive, according to a senior Palestinian official briefed on the preliminary results.

The autopsy showed that the teenager, Mohammed Abu Khdeir, 16, who was buried as a martyr Friday in a funeral that drew thousands, had a head injury and burns over 90 percent of his body, the Palestinian attorney general, Abdelghani al-Owaiwi, wrote on his agency's official website.

The Israeli police are still investigating the attack and have not named any suspects in what is widely seen as an act of revenge by Jews for the abduction-murder last month of three Israeli teenagers in the occupied West Bank.

"It was obvious through autopsy that there was black smoke on the breathing airways, windpipes and in the two lungs," according to the attorney general's website. "This is proof of inhalation of this material during the torch, while he was alive."

The autopsy was conducted by Israeli doctors and attended by the Palestinian coroner, none of whom could immediately be reached Saturday.

Micky Rosenfeld, a spokesman for the Israeli police, said that there had been no breakthroughs as investigators continued to consider both revenge and other possible criminal motives, and that legal restrictions prevented him from discussing details of what they had found so far.

Mohammed's relatives and Palestinian leaders have criticized the police and the Israeli news media for suggesting that the grisly death might have been an honor killing or the result of a family dispute.

Mohammed was sitting on a wall outside a mosque and his home in the East Jerusalem neighborhood of Shuafat at 3:45 a.m. Wednesday, waiting for the dawn prayer, when a gray Hyundai pulled up and two people forced him into the car, according to video footage that news outlets obtained from security cameras. His charred body was found in the Jerusalem Forest about 90 minutes later.

Human rights groups have also lashed out at the police for what they said was a brutal beating by undercover officers of Tariq Khdeir, 15, a U.S.-born cousin of Mohammed who is spending his summer vacation in Jerusalem, and complained that he was being held by the police without charge.