Jonathan McKee, a local pastor, said he received a distressed call from one of his congregants, a woman in her 50s, who has lived in Belfast for over 20 years. Protesters had smashed her windows, targeting her home “because she’s Black,” and her neighbor’s house was on fire, Mr. McKee said in an interview. The woman, who was born in Uganda and is a care worker, is afraid to return home, Mr. McKee said.

“To be burning people out of their homes is not the way forward for this community,” Mr. McKee said.

Chinonso Uche, 32, a nurse who works at a Belfast hospital, said footage of the overnight protests left her fearing for her life on Wednesday. Originally from Nigeria, she has lived and worked in Belfast for five years and said in a phone interview that she had been the victim of racist attacks twice in the last year, including when a rock was thrown at her.

On Tuesday, she and other immigrant staff members ended their shifts early, fearing attacks. She said three of her colleagues were stopped on their way home by people demanding that they confirm that they had the right to work in Northern Ireland. Police officers had to escort at least one of them home, she said.

Mr. Doherty, the community worker and representative, said that he was “hopeful” that tensions would calm, and that people needed to be talked down from further violence by leaders from across the political spectrum.

“It doesn’t matter if you’re Catholic, Protestant, whatever your background is, think of your own children,” he said, adding, “Think of the fear that children went through last night, whenever their home was being torched. I think we need to bring it down to a human level, and respond to this in a way that everyone can move forward together.”

Michael D. Shear and Lynsey Chutel contributed reporting.