A delegation of US diplomats had to cut short an event in the Palestinian city of Bethlehem on Tuesday, an attendee said, after protesters stormed their meeting.
The angry protesters, who were objecting to US President Donald Trump's controversial recognition of Jerusalem as Israel's capital, also threw tomatoes at the delegation's car as they left.
Samir Hazboun, head of the Bethlehem Chamber of Commerce, said they had been holding a training session for local businesspeople about digital commerce with an American expert and a delegation from the US consulate in Jerusalem.
"We were surprised when a number of angry protesters held an extraordinary protest, which forced us to end the course and for the American trainer to leave immediately with the American consulate delegation," he told AFP.
Video footage posted online showed a handful of protesters entering the room and chanting while holding signs opposing Trump's decision.
One sign read "Zionism = Nazism = Fascism".
The American delegation quickly packed up and left, with the protesters throwing what appeared to be tomatoes at their cars, while one man kicked a car.
In response, a US State Department spokesperson said "the United States opposes the use of violence and intimidation to express political views.
"This non-political programme was one part of long-term US engagement to create economic opportunities for Palestinians."
Trump's December 6 recognition of Jerusalem as Israel's capital set off protests among Palestinians, who consider the city to be their capital as well.
The Palestinian leadership has frozen ties with the American administration, and Trump has withheld tens of millions of dollars in aid.