The US’s Minneapolis city Mayor has declared a state of emergency Thursday as protests raged and a police station burned in the tension-filled city where an African American man died in police custody Monday night, Voice of America reported.

The emergency declaration will stay in place for 72 hours and allows officials to deploy emergency regulations with immediate effect.

After hundreds of demonstrators had marched peacefully, a Minneapolis police precinct went up in flames late Thursday. Reporters on the scene said the police presence in the area had been reduced to “zero,” and they were unsure where the police were. Posts on Twitter indicated the police station had been abandoned. Firefighters were also absent. Meanwhile, the city warned that officials had unconfirmed reports that gas lines had been cut and that the building could explode.

Several stores in Minneapolis and the twin city of St. Paul were also set ablaze Thursday night. St. Paul police report officers being hit by rocks and bottles.

The protesters are enraged by the death of George Floyd after a white police officer knelt on his neck while he was in custody, allegedly killing him. CNN reported that the officer had 18 prior complaints filed against him with the Minneapolis Police Department’s Internal Affairs.

Minneapolis police say Floyd resembled a suspect wanted for allegedly trying to spend a counterfeit $20 bill in a food store. Police say he had resisted arrest. Bystanders captured the scene on cellphone video as officers detained Floyd. The video spread when posted online.

“Please, please, please, I can’t breathe. Please, man,” Floyd pleaded while being detained by a white police officer. According to the cellphone video, the officer held Floyd on the ground and knelt on his neck. Floyd was handcuffed.

The officer restraining Floyd urged him to “relax,” but the officer kept his knee on Floyd’s neck after Floyd stopped moving. One witness said he heard Floyd calling out for his mother before dying.

Because of Floyd’s “I can’t breathe,” his death was quickly compared to that of Eric Garner, an unarmed black man in New York who died in 2014 after a white officer placed him in a chokehold while he begged for his life. Garner also told officers, “I can’t breathe,” and the cry became a national rallying point against police brutality.

Rallies were also taking part in other cities Thursday. The Associated Press reported that hundreds of demonstrators stood in the downtown streets and chanted as darkness fell outside the Colorado State Capitol in Denver, where protesters spray-painted graffiti and broke car windows.

The Minneapolis Police Department fired all four officers involved in Floyd’s arrest. The FBI has joined Minneapolis police and the Hennepin County attorney’s office in the investigation. The Justice Department said the investigation is a top priority.