Governor Dennis Daugaard is calling for all US flags in South Dakota to be flown at half-staff in respect for the victims of the shootings at the Washington Navy Yard.

Daugaard says President Obama has called for the flag to be displayed at half-staff until sunset on Friday, September 20 to show respect for the victims, and has invited Governors of the United States to join in the observance.

US officials say 12 people lost their lives.

The alleged shooter, 34-year-old Aaron Alexis, was shot by police.