The United States and a top U.N. official Tuesday separately called for an immediate investigation into the deaths of two Palestinian youths fatally shot last week by Israeli border policemen in the West Bank, Al Arabiya reported.
The young men were shot dead on Thursday as Israeli police responded to demonstrations marking the 66th anniversary of the Nakba -- or "catastrophe" -- of the Jewish state's creation.
The group Defense for Children International-Palestine has released what it said was closed circuit television footage showing the unprovoked deaths of Musaab Nuwarah, 20, and Mohammed Udeh, 17. Israel rejects the footage however, saying it is doctored.
State Department spokeswoman Jen Psaki said the United States had been in contact with the Israeli government.
"We are closely following this incident and the video. We're seeking additional information from the government of Israel," she said in Washington.
"We look to the government of Israel to conduct a prompt and transparent investigation to determine the facts surrounding this incident, including whether or not the use of force was proportional to the threat posed by the demonstrators."
She added: "We are encouraging the government of Israel to conduct their own investigation."
Assistant U.N. secretary general for political affairs Oscar Fernandez-Taranco also urged a probe.
"It is of serious concern that initial information appears to indicate that the two Palestinians killed were both unarmed and appeared to pose no direct threat," said Fernandez-Taranco.
"The U.N. calls for an independent and transparent investigation by the Israeli authorities into the two deaths, and urges Israel to ensure that its security forces strictly adhere to the basic principles on the use of force and firearms by law enforcement officials," he said at a briefing of the U.N. Security Council.
Israel has said the border police had tried to quell a violent demonstration by about 150 Palestinians. But Palestinian leaders have said the slain boys were unarmed and posed no threat, accusing Israel of using "excessive and indiscriminate violence."