WASHINGTON — Police used pepper spray to clear a pro-Palestinian tent encampment at George Washington University and arrested dozens of demonstrators on Wednesday just as city officials were set to appear before hostile lawmakers in Congress to account for their handling of the 2-week-old protest.

The House Committee on Oversight and Accountability canceled the hearing after the crackdown, with its chairman and other Republicans welcoming the police action. House Speaker Mike Johnson said, “it should not require threatening to haul D.C.’s mayor before Congress to keep Jewish students at George Washington University safe.”

Mayor Muriel Bowser, a Democrat, said she and Metropolitan Police Chief Pamela Smith decided to clear the camp because of signs that “the protest was becoming more volatile and less stable.” Among them were indications that protesters had “gathered improvised weapons” and were “casing” university buildings with the possible intention of occupying them, police said.

But Moataz Salim, a Palestinian student at George Washington who has family in Gaza, said the authorities merely “destroyed a beautiful community space that was all about love.”

“Less than 10 hours ago, I was pepper sprayed and assaulted by police,” he told a news conference held by organizers. “And why? Because we decided to pitch some tents, hold community activities and learn from each other. We built something incredible. We built something game-changing.”

Tensions have ratcheted up in standoffs with protesters of the Israel-Hamas war on campuses across the United States and increasingly in Europe. Some colleges cracked down immediately. Others have tolerated the demonstrations. Some have begun to lose patience and call in the police over concerns about disruptions to campus life and safety.

Police also moved in Tuesday night to break up an encampment at the University of Massachusetts. Video from the scene in Amherst showed an hourslong operation as dozens of officers in riot gear systematically tore down tents and took protesters into custody. The operation continued into early Wednesday. Police said about 130 people were arrested after protesters refused orders to disperse.

“I found it to be a complete overreaction,” said Lucas Ruud, editor-in-chief of The Massachusetts Daily Collegian. “It was a completely unnecessary show of force.” The staff of the college newspaper counted more than 100 police vehicles on campus for the crackdown.

In Washington, police said they arrested 33 people at the George Washington protest, including for assault on a police officer and unlawful entry. They confirmed they used pepper spray outside the encampment against protesters who were trying to break police lines and enter.

Two Democratic lawmakers appeared at a news conference with five of the students who had been arrested. “I want all Republicans and Democrats to know that they cannot arrest their way out of this growing dissent,” said Rep. Rashida Tlaib of Michigan.