A “profoundly troubled” United States has condemned reports an American teenager detained in Israel was “severely beaten” while in police custody, amid heightened tensions with Palestinians.

The parents of Tariq Abu Khder, a 15-year-old cousin of a Palestinian youth murdered earlier this week, have told news agency AFP their son was arrested in Shuafat after being beaten by police on Thursday during his holiday stay in the area.

State Department spokeswoman Jen Psaki said on Saturday the United States “strongly condemn(s) any excessive use of force,” referring to the alleged beating.

Clashes have erupted in recent days, sparked by the abduction and murder of Tariq’s cousin Mohammed Abu Khder, 16, as autopsy reports showed he was burned alive.

Palestinians said Jewish extremists killed him in revenge for the kidnapping and murder in the West Bank last month of three Israeli teenagers.

Tariq was still in Israeli custody, Psaki confirmed, adding that a US consulate official had visited him on Saturday.

“We are profoundly troubled by reports that he was severely beaten while in police custody,” Psaki said in a statement.

“We are calling for a speedy, transparent and credible investigation and full accountability for any excessive use of force.”

Rocket fire targeting Israel from Gaza has also increased, raising fears of an escalation with the Islamist movement Hamas, which controls the Palestinian enclave.