"There's a lot of anxiety going on, a lot of emotions flowing in," a member of the group said, adding that "it's very hard to imagine anything like this with such a great, loving family."
There are about 500,000 Sikhs in the US. The majority worldwide live in India.
This comes as Sikh rights groups have reported a rise in bias attacks since the September 11, 2001 attacks. The Washington-based Sikh Coalition has reported more than 700 assaults on Sikhs in the US since September 2001.
Last year, one woman and five men were killed and three others were wounded when white supremacist Wade Michael Page opened fire at a Sikh temple in a Milwaukee suburb in Wisconsin.
A Sikh man has murdered his wife and two young children before hanging himself in an apparent triple murder, suicide in the US state of Georgia.
The homicides occurred early Monday morning in a suburban neighborhood near Atlanta, Georgia, police reported.
Investigators said five-year-old Gurtej Singh Grover and 12-year-old Sartaj Singh Grover died of stab wounds to their necks, while their mother, 47-year-old Damanjit Kaur Grover, died from head trauma. The father of the family, 52-year-old Shivinder Singh Grover, hanged himself.
There is no word yet on the killer’s motives.
Members of the Sikh community gathered at the Gurudwara Sahib congregation to pray and console each other for the loss.