Mr Mamdani will become the first Muslim, African-born, Indian-American mayor of New York by the time he is sworn into office on January 1, 2026.
A man opened fire in a New York high-rise building on Monday evening, killing no fewer than four people before taking his own life, authorities said.
The temperature is expected to rise in more states in the U.S., including Philadelphia, Boston, Baltimore, Memphis, Atlanta, Dallas, Indianapolis and others.
Mr Adams, at a press conference on Thursday, rejected calls demanding his resignation.
U.S. Attorney Damien Williams said the mayor participated in corruption involving bribery by foreigners for almost a decade, thereby violating public trust.
Details of his indictment, expected to be disclosed by federal prosecutors on Thursday, will make him the first sitting mayor in modern New York City history to be criminally charged.
Mr Adams said he would no longer tolerate the shipping of migrants from Republican states into New York City when the city faces an unprecedented housing crisis.
The mayor thanked Nigerians for their support when he was running to become the mayor of the City of New York.
Mr Frank’s arrest came after investigators found a 9mm Glock handgun, a bag containing explosives and a credit card abandoned at the scene.
The Nigerian community had on June 5 endorsed Adams as the New York City Mayoral candidate after consultations among Nigerians.
