For the second time in less than a week, the president is ordering flags lowered to memorialize Americans killed in a mass shooting incident.

President Joseph Biden on Tuesday issued a proclamation “as a mark of respect for the victims of the senseless acts of violence perpetrated on March 22, 2021, in Boulder, Colorado.”

On Monday evening, a 21-year-old man opened fire inside a crowded Colorado supermarket. The shooting killed ten people, including a police officer who was the first to respond to the King Soopers store, according to the Associated Press.

Tuesday afternoon, Biden ordered flags lowered to half-staff immediately, until sunset Saturday, March 27.

Flags are to be lowered, according to the proclamation, “at the White House and upon all public buildings and grounds, at all military posts and naval stations, and on all naval vessels of the Federal Government in the District of Columbia and throughout the United States and its Territories and possessions until sunset, March 27, 2021. I also direct that the flag shall be flown at half-staff for the same length of time at all United States embassies, legations, consular offices, and other facilities abroad, including all military facilities and naval vessels and stations.”

Flags were lowered last week following attacks in Woodstock and Atlanta, Ga., that claimed the lives of eight people.