"If the Arab youth was murdered because of nationalistic motives, then this is a horrible and horrendous act. There is no difference between Arab blood and Jewish blood. Murder is murder. There is no forgiveness or justification for any murder."

After being taken in by Israeli police for questioning, Abu Khadeir's father said DNA tests proved the body was that of his missing son. Inside the family's home, while protests raged outside, the teen's mom, Suha Abu Khdeir, sat in stunned silence, sometimes breaking into tears, in a room filled with relatives and friends, Maan News said.

Ansam Abu Khdeir, a cousin of the slain teen, said witnesses wrote down the car's license plate number and police are examining the CCTV footage.

Witnesses told Palestinian news website Maan News that surveillance footage showed what appeared to be Israelis forcing Abu Khdeir into their car in front of a supermarket before speeding off.

The body of Mohammed Abu Khdeir, from the Shuafat neighborhood, was found reportedly burned and with signs of torture by police in a forest outside Jerusalem.

The murder of the Palestinian teen highlights a growing fear that more violent acts will be carried out, not between the Israeli military and Palestinian armed groups, but by vigilante groups on both sides taking matters into their own hands.

A 17-year-old Palestinian boy from East Jerusalem was abducted and killed early Wednesday — a suspected act of revenge for the killing of three Israeli youths, whose disappearances and deaths have heightened tension in the region.

Prior to the kidnappings, Palestinians suffered a pattern of hate crimes by right-wing Israelis in acts of reprisal known as price-tag attacks. Such incidents have tended to increase when the Israeli government tries to slow illegal settlement construction.

On Tuesday night, hard-line Israelis marched through Jerusalem chanting, “Death to the Arabs.” Israeli police arrested dozens of them after they tried to break into a McDonald’s, reportedly searching for Arab workers.

The killing comes amid ongoing tension in the area following the discovery Monday of the bodies of three Israeli teens kidnapped last month.

Two Palestinians sustained fractures after being assaulted by Israeli security forces, he said, adding that soldiers were firing live ammunition and 17 Palestinians had been hospitalized. Residents said the clashes were the biggest they have seen in years. Protests also occurred across the West Bank.

At least 37 Palestinians, including journalists, had been hit by rubber-coated steel bullets and six were injured by shrapnel in Shuafat, Red Crescent paramedic Rajih al-Hawarin told Maan News .

Abu Khdeir's killing sparked protests in occupied East Jerusalem — hundreds of Palestinian youths threw stones at Israeli security forces. Soldiers retaliated by launching deafening sound bombs, tear gas, rubber-coated steel bullets and reportedly live ammunition at the youths.

A Palestinian throws a stone toward an Israeli military jeep on Wednesday, during clashes with Palestinians in an early morning operation in the West Bank city of Jenin. Mohammed Ballas/AP

Pattern of attacks

The U.S. State Department included price-tag attacks for the first time in its annual report on "terrorism" published this spring. At least 400 attacks were carried out in 2013, most of which went unprosecuted, according to the United Nations. Israel set up a special unit in the West Bank to attempt to control hard-line settlers, and this spring top justice officials even considered classifying groups that carry out price-tag attacks as "terrorist" organizations, according to The New York Times.

Israeli Prime Minister Benjamin Netanyahu said Wednesday that law enforcement will investigate the murder of the Palestinian teen and called on both sides not to take the law into their own hands. He condemned the killing as a “heinous murder.”

Palestinian President Mahmoud Abbas had earlier asked that Israel take real measures on the ground to stop the violent escalation that has led to the deaths of 15 Palestinians since the beginning of June.

“We condemn all Israeli measures, the attacks that have been ongoing for weeks all the way to the crime committed this morning,” Nabil Aburdeineh, a spokesman for Abbas, told Al Jazeera. “The Palestinian leadership has discussed many options, including our right to approach [United Nations] organizations and defend ourselves.”

Hundreds of extra Israeli police were deployed around Jerusalem in an attempt to prevent further violence. The city's mayor, Nir Barkat, denounced the murder and also called for calm.

“This is a horrible and barbaric act which I strongly condemn. This is not our way and I am fully confident that our security forces will bring the perpetrators to justice,” Barkat said in a statement. “I call on everyone to exercise restraint.”

The United States condemned Abu Khdeir's murder on Wednesday.

"It is sickening to think of an innocent 17-year-old boy snatched off the streets and his life stolen from him and his family. There are no words to convey adequately our condolences to the Palestinian people," U.S. Secretary of State John Kerry said.

"The world has too often learned the hard way that violence only leads to more violence and at this tense and dangerous moment, all parties must do everything in their power to protect the innocent and act with reasonableness and restraint, not recrimination and retribution."

Israeli forces arrested 42 Palestinians overnight across the West Bank, the army said Wednesday, as part of the continuing crackdown on Hamas in the wake of the three youths’ killings, which Israel blames on the group. Hamas has denied any involvement in the June 12 kidnapping.

The Israeli military has launched scores of airstrikes on the Gaza Strip in the past weeks that have killed two and injured several, and armed groups in the territory have shot dozens of rockets into southern Israel.

Israeli warplanes launched airstrikes on Gaza on Wednesday. No injuries were immediately reported.

Israeli settlers reportedly set fire to a farm in the northern West Bank Wednesday, Palestinian officials said. And Ghassad Daghlas, a Palestinian official responsible for monitoring settler activity, told Maan News that a group of Israelis set fire to a sheep farm outside Nablus overnight.

The settlers, from the illegal settlement of Itamar near Nablus, spray-painted the words “blood vengeance” and “price tag” in Hebrew on the outer walls of the farm.

On Tuesday, several other incidents of Israeli reprisal attacks against Palestinians in Jerusalem and the West Bank were reported — including a reported hit-and-run that left a 9-year-old girl seriously injured.