President Joe Biden ordered flags to be flown at half-staff on Tuesday, following a mass shooting at an Independence Day parade in Highland Park, Illinois, where authorities say a gunman killed six people and injured dozens.

Biden ordered that flags at all public buildings and grounds, military posts and naval stations and vessels be flown at half-staff until Saturday “as a mark of respect for the victims of the senseless acts of gun violence perpetrated on our Independence Day,” the White House said Tuesday.

The announcement comes in the wake of the July 4 shooting in the Chicago suburb that amounted to what the mayor called the city’s “bloodiest day” and adds to a growing list of mass shootings that have devastated the country in recent weeks.

In a statement Monday, Biden said he and the first lady were “shocked by the senseless gun violence that has yet again brought grief to an American community,” while pointing to the signing of the first major gun reform legislation passed in decades last month as a step in the right direction. Still, he added that he is “not going to give up fighting the epidemic of gun violence.”

“But we got a lot more work to do,” Biden reiterated during remarks celebrating the July 4th holiday. “We got to get this under control.”