A suspicious package with two vials of blood prompted a lockdown at the Republican National Committee headquarters in Washington, D.C., on Wednesday, the authorities said.

The vials were addressed to former President Donald J. Trump, according to a law enforcement official who insisted on anonymity because the person was not authorized to speak publicly about the matter.

The package also contained ice packs and a Korean-language Bible, according to Brianna Burch, a spokeswoman for the U.S. Capitol Police, who said that the incident remained under investigation.

The R.N.C. and Mr. Trump’s campaign did not immediately comment on the situation, which drew a heavy law enforcement response and played out just a few blocks away from the U.S. Capitol.

At 7:45 a.m. Eastern time, officers responded to the 300 block of First Street, Southeast, after receiving a report about the suspicious package, the authorities said. Hazardous materials teams removed the contents of the package, and the lockdown order was lifted shortly before 10 a.m.

The authorities did not say how many people were inside the R.N.C.’s headquarters at the time.

Television news broadcasts showed the area blocked off by police vehicles and yellow tape.

It was not the first time that a startling discovery had been made at the R.N.C.’s office.

On Jan. 6, 2021, the day that the U.S. Capitol was attacked by Mr. Trump’s supporters, who were seeking to overturn his election defeat, a pipe bomb was discovered at the R.N.C.’s headquarters. A bomb squad destroyed the device.

That same day, another suspicious package forced the evacuation of the Democratic National Committee’s headquarters in Washington, which is also a few blocks from the Capitol.