US President Barack Obama has ordered American flags to be flown at half mast until Saturday to honour five US servicemen who died in a shooting rampage in Tennessee last week.
Four marines and one sailor were killed when 24-year-old Mohammad Youssuf Abdulazeez opened fire on two military centres in Chattanooga. The gunman died in a shootout with police.
Obama ordered the flags lowered on Tuesday, "as a mark of respect for the victims of the senseless acts of violence."
"I hereby order that the flag of the United States shall be flown at half-staff 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," Obama said in a statement.
He also ordered flags at embassies, consulates, military facilities and naval vessels abroad to be flown at half-staff.
The directive is in place until sunset Saturday.
"Our thoughts and prayers as a nation are with the service members killed last week in Chattanooga. We honour their service," Obama said.
Investigators are looking into motives behind the killings, with authorities probing Abdulazeez's travel abroad and his communications and activities on social media.
Authorities have said they are treating the case - a grisly scene reminiscent of other shooting rampages at US military installations - as an "act of terrorism."