Anti racial discrimination protests in Portland, the United States, are continuing. Two law enforcement officials said Friday that the Portland government received anonymous threats on the 20th to attack federal buildings, and at least two buildings were then closed. The FBI is investigating the credibility of the threat. According to the associated press and other media reports, many federal buildings in Portland were closed due to the threat of the attack. The lower City Court building, the office of the U.S. federal bankruptcy court and the two child development centers in the federal building were closed on the same day. FBI officials said they had launched an investigation with local law enforcement agencies, and new progress would be announced. Two anonymous officials told the associated press that it was not known whether the incident was related to the continued local demonstrations. This week, Portland protestors mainly protested against the U.S. immigration and customs enforcement agency. From the evening of 20 to the morning of 21, about 100 people demonstrated. During the demonstration, stones and debris were thrown at law enforcement officers and laser irradiation was used. Three people were arrested.