WASHINGTON-- The United States said Saturday that it was "profoundly troubled" by an American citizen of Palestinian origin being beaten in Israeli police custody, calling for steps taken to keep innocents from harm amid rising rivalry between the Israelis and the Palestinians.

Tariq Khdeir, a 15-year-old boy from Tampa, Florida, who had been visiting his Palestinian relatives in Jerusalem, was detained and beaten by Israeli police when he joined a demonstration Thursday following the death of his cousin, Mohammed Abu Khdeir, according to news reports.

State Department spokeswoman Jennifer Psaki confirmed that Khdeir is an American citizen and that he was visited by an official from the U.S. consulate general in Jerusalem Saturday.

"We are profoundly troubled by reports that he was severely beaten while in police custody and strongly condemn any excessive use of force," Psaki said in a statement. "We are calling for a speedy, transparent and credible investigation and full accountability for any excessive use of force."

The spokeswoman also voiced "grave concern" about the increasing violent incidents and urged both sides to take steps to "restore calm" and prevent harm to innocents.

Mohammed Abu Khdeir, a Palestinian teenager, was murdered Wednesday in what was seen as a revenge for the deaths of three Israeli teenagers who were abducted in the West Bank last month.

Tensions and violence escalated between the Israelis and the Palestinians due to the tragic incidents, raising concerns around the world.