Rao said the US Deputy National Security Advisor spoke to her from White House on Sunday to convey "sincerest condolences" from US President
Barack Obama [ Images ] over the shooting incident in which seven people including the gunman, have been killed.
"Mr Brennan (John) assured me these tragic killings would be fully investigated, that Sikh community is precious part of fabric of American nation," she wrote on the micro-blogging site Rwitter.
The US Under Secretary of State for Political Affairs Wendy Sherman had also telephoned her to "express heartfelt condolences" on the dastardly and horrible killings in Wisconsin, Rao said.
"Our hearts bleed for precious and innocent lives lost in Oak Creek. This is a very tragic time for our community. We must maintain calm," said the Indian ambassador, who was quick to dispatch her Chicago consul general to Milwaukee for an on the spot assessment of the situation.
Rao also thanked her Pakistani counterpart Sherry Rehman who used Twitter to express her condolences over the tragic incident.
"Saddened at the tragedy. Our prayers with the victims and their families in the Wisconsin shooting at the Sikh temple," Rehman wrote in the Twitter website addressed to Rao.
"Thank you. This is a moment of deep sadness. Violence is so meaningless," said Rao.
Rao has nearly 40,000 followers on the micro-blogging site.