Kari Lake's office on lockdown after campaign staffer opened envelope with 'suspicious' substance inside

The office of Arizona GOP Senate candidate Kari Lake was put on lockdown Tuesday after a campaign staffer opened a package with a "suspicious" substance. 

A campaign spokesperson told Fox News Digital that an intern at the campaign's Phoenix office opened an envelope with a suspicious substance and a note that said, "caution anthrax." 

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The campaign called authorities, prompting a response from multiple law enforcement agencies and a hazmat team. 

Authorities have not confirmed if the substance was anthrax. The campaign spokesperson said the substance is now being tested. 

"The radical left, with help from the mainstream media, has escalated its attacks against me from baseless smears and legal harassment to physical threats. Today, my office received a suspicious envelope, potentially containing anthrax - an attempt to intimidate and silence me," Lake said in a statement. "This isn't just about me; it's an attack on our movement. I won't be intimidated, and those responsible must be brought to justice. The time to unite against these dangerous, un-American tactics is now."