Thread by @NBCNews

BREAKING: US Capitol on lockdown due to security incident.

We will provide updates here as we receive more information. NBCNews.com

Message sent to congressional offices: "Due to ... security threat located. All U.S. Capitol Campus Buildings, no entry or exit is permitted at this time. You may move throughout the building(s) but stay away from exterior windows and doors. If you are outside, seek cover."

BREAKING: Security incident involves a car trying to crash a barricade at the U.S. Capitol, @PeteWilliamsNBC reports on @MSNBC.

@PeteWilliamsNBC @MSNBC BREAKING: At least 1 person has been shot outside the US Capitol, Washington D.C. Fire and EMS Dept. says.

@PeteWilliamsNBC @MSNBC BREAKING: Capitol Police: "USCP is responding to the North Barricade vehicle access point along Independence Avenue for reports someone rammed a vehicle into two USCP officers. A suspect is in custody. Both officers are injured. All three have been transported to the hospital."

We will air an @NBCNews Special Report momentarily.

BREAKING: NBC News Special Report:

At least 2 officers injured, suspect in custody after vehicle tried to ram a barricade at the US Capitol.

twitter.com/i/broadcasts/1…

Image from the US Capitol show a vehicle that crashed into a barricade.

BREAKING: Shooting at US Capitol as vehicle rams barricade; at least 1 person shot; officers injured; suspect taken into custody, authorities say.

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BREAKING: After striking 2 US Capitol Police officers, the driver jumped out of the car with a knife and was shot by Capitol police, 2 law enforcement officials tell @NBCNews.

BREAKING: US CAPITOL LATEST

• Vehicle rammed barricade at Capitol

• After striking 2 Capitol Police officers, driver jumped out of car with a knife and was shot by Capitol police

• At least 2 officers injured

• Suspect in custody

nbcnews.to/3wfMLzw

Senate Minority Leader McConnell: "Praying for the United States Capitol Police officers who were attacked at the Capitol. We are still learning what’s taken place. Grateful to all the USCP and first responders who are on the scene."

BREAKING: Suspect involved in vehicle ramming at US Capitol has died, @PeteWilliamsNBC reports on @MSNBC.

@PeteWilliamsNBC @MSNBC National Guard troops arrive along Constitution Avenue as law enforcement responds to vehicle ramming at US Capitol on Friday.

📷 Drew Angerer / Getty

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BREAKING LIVE: @NBCNewsNOW coverage as law enforcement responds to vehicle ramming at US Capitol; at least two officers injured; suspect dead.

twitter.com/i/broadcasts/1…

@NBCNewsNow BREAKING LIVE: Authorities update on vehicle ramming at US Capitol.

twitter.com/i/broadcasts/1…

@NBCNewsNow Message sent to congressional offices: "The external security threat located at all of the U.S. Capitol Campus Buildings has been neutralized, but the USCP is continuing to investigate out of an abundance of caution and there is still no entry or exit permitted at this time."

@NBCNewsNow BREAKING: A US Capitol officer who was injured in vehicle attack today has died, police chief says.

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“It is with a very, very heavy heart that I announce one of our officers has succumbed to his injuries,” acting USCP chief says.

"This is has been an extremely difficult time for US Capitol police after the events of Jan. 6 and now the events that have occurred here today."

BREAKING: US CAPITOL LATEST

• 1 USCP officer dead after vehicle rammed barricade at Capitol, says acting police chief

• After striking 2 Capitol Police officers, driver jumped out of car with a knife and was shot by Capitol police; suspect has died

nbcnews.to/3wfMLzw

Procession for USCP officer killed in vehicle attack at the US Capitol on Friday afternoon.

US Capitol Police officers salute as procession carries the body of William "Billy" Evans, an 18-year-veteran of USCP who was killed in a vehicle attack at the US Capitol on Friday afternoon.

📷 Jose Luis Magana / AP

nbcnews.to/3wfMLzw

President Biden statement on vehicle attack at US Capitol:

"Jill and I were heartbroken to learn of the violent attack at a security checkpoint on the U.S. Capitol grounds ... We send our heartfelt condolences to Officer Evans’ family, and everyone grieving his loss."

NEW: President Biden orders flags to be flown half-staff at White House and all public buildings and grounds through Tuesday following vehicle attack at US Capitol that killed a USCP officer.

3rd time flags ordered lowered in 2 weeks, following Atlanta and Boulder attacks.

US Capitol Police officer also injured in vehicle attack at the Capitol earlier today is in stable and non-life-threatening condition, Capitol Police officials say.