Congresswoman Lauren Boebert criticized for tweeting about Biden during shooting in her state

Second Amendment advocate Lauren Boebert is facing criticism for tweeting about Joe Biden's "lid" as dozens of police rushed to a shooting at a Colorado grocery store.

Police tweeted an active shooter alert in Boulder shortly before 3pm local time, with a video showing a handcuffed man, shirtless and covered in blood, escorted from the building about 30 minutes later.

"The White House just called a lid at 1.13 pm today. Biden is back in the basement, figuratively at least," Ms Boebert tweeted.

"Meanwhile, the country is in chaos and the border is coming apart at the seams."