SANTIAGO, Chile — Hundreds of demonstrators dressed in black barged into a cathedral in a city in southern Chile on Saturday and interrupted the installation ceremony for the city’s new Roman Catholic bishop, Juan Barros, whom they accuse of complicity in a notorious case of clerical sexual abuse, blocking his passage and shouting, “Barros, get out of the city!”

The scene inside the Cathedral San Mateo de Osorno was chaotic, with television images showing clashes between Barros opponents, carrying black balloons, and Barros supporters, carrying white ones. Radio reports said several protesters tried to climb onto the altar where Bishop Barros was standing. After the ceremony, he left the cathedral through a side door escorted by police special forces. Outside, about 3,000 people, including local politicians and members of Congress, held signs and chanted demands that he resign.

Weeks of protests, candlelight vigils and letters to Pope Francis were not enough to persuade him to rescind his decision in January to appoint Bishop Barros to lead the Diocese of Osorno, 570 miles south of the capital, Santiago. Bishop Barros was a close associate of the Rev. Fernando Karadima, a prominent Santiago priest whom the Vatican found guilty of sexual abuse in 2011. Father Karadima, now 84, was ordered to retire to a “life of prayer and penitence.”

The appeal was also a test case for the pope’s stated policy of zero tolerance for clerical abuses.

“We are used to the blows by the Chilean Catholic hierarchy, but it’s especially hurtful when the slap in the face comes from Pope Francis himself,” Juan Carlos Cruz, 51, who said he was abused by Father Karadima in the ’80s, said in a telephone interview. “We hoped he was different.”