UPDATE - US Capitol Police responds to suspicious package at Republican National Committee headquarters

ADDS DETAILS; CHANGES HEADLINE, LEDE

By Diyar Guldogan

WASHINGTON (AA) - The headquarters of the Republican National Committee in Washington DC was briefly put on lockdown Wednesday because of an investigation into a suspicious substance, according to US Capitol Police.

"This morning, we responded to the 300 block of First Street, SE, for the report of a suspicious package. The package was cleared by our Hazardous Incident Response Division. It contained two vials of blood," Capitol Police wrote on X.

The source of the package and its contents will be further investigated, it added.