JAKARTA – One protester died and several were injured after tens of thousands of Muslims flooded the streets of Jakarta to protest against the city’s Christian and ethnic Chinese governor after allegations that he insulted Islam. President Joko Widodo said after midnight that he was “disappointed” by the violence — demonstrations that raised fears that anti-Chinese sentiment, which erupted in deadly violence in 1998, could once again flare. Widodo urged the protesters to disperse, saying that the accusations against the governor, Basuki Tjahaja Purnama, would be handled by the police. “The demonstration shows that this can easily be mobilized, especially among the poor in Jakarta,” said Charlotte Setijadi, an expert on Chinese Indonesians at the Institute of Southeast Asian Studies in Singapore. An estimated 2% to 3% of Indonesia’s 250 million people are of Chinese descent, and though prominent in business, they have historically been weak politically. Rumors spread Friday that the city’s ethnic Chinese community could be targeted by angry mobs, with police struggling to curtail a group of protesters trying to break into the governor’s residence in the north of the city.