President Barack Obama said he was "deeply saddened" and pledged his administration's commitment to fully investigate the shooting.
At this difficult time, the people of Oak Creek must know that the American people have them in our thoughts and prayers, and our hearts go out to the families and friends of those who were killed and wounded.
As we mourn this loss which took place at a house of worship, we are reminded how much our country has been enriched by Sikhs, who are a part of our broader American family.
More top news
Donald Trump has wasted no time making his mark on international matters as well as domestic. So how will his presidency affect the world?
Another cold, frosty and foggy night for many. Northern and western areas will see thickening cloud, patchy rain and milder temperatures.
Temperatures have already plunged to -12C in some parts of the UK this winter - but Thursday could be the coldest day yet.