Washington — The Republican National Committee headquarters in Washington, D.C., was placed on lockdown early Wednesday morning after two vials of blood were found in a suspicious package received by the RNC, U.S. Capitol Police confirmed. 

The source of the blood is unclear and is under investigation. Capitol Police, which took the lead on the investigation, confirmed its Hazardous Incident Response Division had examined the package and cleared it, and spokesperson Brianna Burch said the Capitol Police would further investigate the source of the package and its contents.

The party headquarters has been targeted in the past — on Jan. 5, 2021, pipe bombs were sent to both the Republican and Democratic party headquarters in Washington, D.C., and Vice President Kamala Harris was evacuated from the DNC headquarters. No one was ever arrested in connection with that incident, which occurred on the eve of the Jan. 6, 2021 attack on the U.S. Capitol.