US and UN condemn killing of Palestinian boy in Israel
The US and UN have condemned the abduction and murder of a Palestinian teenager in Israel, which sparked fierce clashes in East Jerusalem.
US Secretary of State John Kerry called it "sickening" while the UN demanded justice over the "despicable act".
Mohammed Abu Khdair, 17, was seen being forced into a car early on Wednesday.
Palestinian leaders expressed outrage over the killing, amid claims it was in revenge for the murder of three Israeli teenagers.
Palestinian President Mahmoud Abbas accused Jewish settlers of killing Mohammed Abu Khdair, calling for the "strongest punishment against the murderers if [Israel] truly wants peace".
Agence France-Presse news agency quoted the militant group Hamas as telling Israeli leaders: "Our people will not let this crime pass... You will pay the price for these crimes."
Israeli leaders also condemned the killing, pledging a full investigation.
Prime Minister Benjamin Netanyahu said it was "despicable" and that he had ordered police to work "as quickly as possible to find out who was behind the heinous murder of the youth".
He called on both sides "not to take the law into their own hands".
John Kerry said there were "no words to convey adequately our condolences to the Palestinian people".
Analysis: Yolande Knell, BBC News, Jerusalem
The Israeli police insist they are taking the case of Mohammed Abu Khdair seriously and that a thorough investigation is under way. They said they began a search for him as soon as he was reported missing.
Most Palestinian residents of East Jerusalem have already made their minds up about the motivation for the murder.
Tensions are now set to rise again particularly with a funeral expected to take place on Thursday. Locals say they are worried this death could trigger a new cycle of violence.
He said: "All parties must do everything in their power to protect the innocent and act with reasonableness and restraint, not recrimination and retribution."
A spokesman for UN Secretary General Ban Ki-moon said that "the heinous act by enemies of peace aims to further entrench division and distrust and to widen the conflict. It must not be allowed to succeed".
UK Prime Minister David Cameron said he was "appalled by the murder of a Palestinian teenager".
The family of one of the three murdered Israeli teenagers also issued a statement condemning the latest killing.
"If the Arab youth was murdered because of nationalistic motives then this is a horrible and horrendous act," the statement from the family of Naftali Frenkel said.
Israeli police have urged caution over the motives for the killing, saying they are still investigating.
Clashes erupted outside the teenager's home in the Arab district of Shufat in East Jerusalem after news broke of the discovery of the body.
Protesters threw stones at officers, who responded by firing sound bombs, tear gas and rubber bullets.
At least 35 people were injured by the rubber bullets, reports said.
The family of Mohammed Abu Khdair have confirmed the body found on Wednesday in a forest near Givat Shaul, in the western outskirts of Jerusalem, was his.
The body was partly burned and bore marks of violence.
Witnesses said he was abducted near his father's shop in Shufat.
A relative said he saw two men approach the boy and ask for directions before bundling him into a car.
Witnesses wrote down the car's number plate and police are examining CCTV footage.
The killing came a day after funerals were held in the West Bank for the three Jewish seminary students whose bodies were found near the city of Hebron on Monday, two-and-a-half weeks after they were abducted.
Scores of Israelis had angrily protested in Jerusalem after the funerals, some yelling "death to Arabs".
Israel's military said it was investigating reports that soldiers had posted calls for revenge on Arabs on social media networks, saying if true it would treat the matter with utmost severity.