WASHINGTON – The mayor of Tulsa, Oklahoma, imposed a curfew ahead of President Donald Trump's campaign rally there, prompting officers to move out supporters who had been camping out in front of the arena.

Mayor G. T. Bynum announced the order Thursday evening, citing the expected crowds of more than 100,000, the planned protests and the civil unrest that has already erupted in the city and around the nation this month.

Bynum also said he's received information from the Tulsa Police Department and other law enforcement agencies "that shows that individuals from organized groups who have been involved in destructive or violent behavior in other states are planning to travel to the City of Tulsa for purposes of causing unrest in and around the rally."

Bynum said the order is needed to protect health and safety and preserve lives and property.

The curfew of parts of the city's downtown started at 10 p.m. Thursday and is in effect until 6 a.m. Saturday. It begins again at the conclusion of Trump's rally and continues into Sunday morning.

“Big crowds and lines already forming in Tulsa,” Trump tweeted Friday morning, hours after the curfew went into effect.

Big crowds and lines already forming in Tulsa. My campaign hasn’t started yet. It starts on Saturday night in Oklahoma!

— Donald J. Trump (@realDonaldTrump)June 19, 2020

He also issued  this warning: "Any protesters, anarchists, agitators, looters or lowlifes who are going to Oklahoma please understand, you will not be treated like you have been in New York, Seattle, or Minneapolis. It will be a much different scene!"

Trump supporters began lining up outside the BOK Center days in advance of the rally. 

"Sacrificing a week of our lives is nothing for what Trump has done for us," Robin Stites, who arrived on Monday to secure the No. 2 place in line, told the The Oklahoman earlier this week.

In a Facebook post Thursday evening, the Tulsa Police Department said anyone in violation of the mayor's executive order will be asked to leave the area. Those who refuse may be cited or arrested.

In addition to the curfew, the order bans Molotov cocktails or other combustible devices.

"This is an unprecedented event for the City of Tulsa and has hundreds of moving parts," the post said. "We are asking for everyone’s help in making this a safe event for all citizens."