Government sources said the deputy chief of mission in the Indian embassy in Washington, Arun K Singh, took up the issue with Robert Blake, assistant secretary of state for South and Central Asian Affairs, on Monday itself.
India has written to NBC, the TV network that hosts Leno's show. "This is completely unacceptable," said visiting overseas Indians affairs minister Vyalar Ravi on Sunday.
Ravi termed the gag by The Tonight Show host as objectionable and said the Indian embassy in Washington would raise the issue. "The Golden Temple is the Sikh community's most sacred place. Even our prime minister went there to pray in the New Year. I believe the person involved is not that ignorant," he said.
The US state department spokeswoman Victoria Nuland said the US had not communicated with India on the issue but that the US Constitution strictly protected freedom of speech.
"I hope (Leno will) be appreciative if we make the point that his comments are constitutionally protected in the US under free speech and, frankly, they appeared to be satirical in nature," Nuland said.