Washington — The Republican National Committee’s Washington headquarters was briefly evacuated on Wednesday afternoon, as police investigated two vials of blood that had been addressed to former President after the presumptive presidential nominee’s recent announcement to seek the 2024 Republican nomination.

Hazardous-materials teams were called in after the vials were discovered, according to the U.S. Capitol Police, who said they would continue to investigate. It was unclear if anyone came into contact with the blood and to whom it belonged.

The vials were addressed to Trump, according to a person familiar with the situation but not authorized to speak about it publicly. It was unclear whether any message accompanied the vials explaining why they were sent.

The RNC chairman, Michael Whatley, decried the “revolting attack” but did not offer more details.

“We are thankful to law enforcement, who responded quickly and ensured everyone’s safety. The lockdown has been cleared and staff has resumed their office duties because we remain unintimidated and undeterred in our efforts to elect President Trump to the White House,” Whatley said in a statement.

White House press secretary Karine Jean-Pierre condemned “any form of threats,” adding, “That has no place in our politics, no place anywhere.”

The U.S. Secret Service did not immediately return messages seeking comment. The Metropolitan Police Department and the local fire department referred comment to the Capitol Police.

Earlier Wednesday, the Capitol Police issued a statement advising people to avoid the block where the RNC is located, a short walk southeast of the Capitol. The House sergeant at arms, the U.S. House of Representatives’ chief law enforcement and protocol officer, sent out information advising traffic restrictions in the area “due to law enforcement activity at the RNC.”

Trump’s  — including his daughter-in-law, , as the party’s national vice chair and former North Carolina GOP Chairman Michael Whatley as RNC chairman — , completing his takeover of the national party as he closes in on a third straight GOP presidential nomination. A Trump campaign senior adviser, Chris LaCivita, has taken over as the RNC chief of staff.

Wednesday’s situation comes less than two months from  in Milwaukee, where Trump is slated to become the party’s official 2024 nominee and significant protests are expected. According to a letter sent last month to the Secret Service, RNC counsel Todd Steggerda asked officials to keep protesters back farther from the site than had been originally planned, arguing that an existing plan “creates an elevated and untenable safety risk to the attending public.”