Palestinians threw eggs at a delegation including New York City Council members visiting the occupied West Bank on Thursday, AFP reporters said, amid anger over US President Donald Trump's recognition of Jerusalem as Israel's capital.
Several members of the council and New York civil society groups were meeting a Palestinian polling company in the city of Ramallah, the polling company confirmed.
As they left they were pelted with eggs by several dozen protesters, who also chased their bus. Palestinian security forces protected the Americans.
Protesters held signs reading "The US is part of the problem, not the solution."
The State Department condemned the event. "The United States absolutely opposes the use of violence or intimidation to express political views," it said.
"This type of action is unmistakably counterproductive to Palestinian interests; it serves only to ensure that Americans are unable to hear or consider Palestinian perspectives."
One of the demonstrators, Salah al-Khawaja, said he had come to show his opposition to Trump's December 6 recognition of Jerusalem as Israel's capital.
Palestinians see the eastern part of the city as the capital of their future state and the US move broke with decades of international consensus that Jerusalem's status should be negotiated between the two parties.
"Today there was a reaction from the Palestinian people and popular activists, a reaction to this dishonourable and awful reception" by the polling company, Khawaja said.
Last month demonstrators disrupted a meeting between US diplomats and the chamber of commerce in the Palestinian city of Bethlehem.