US lawmakers and influential Indian-Americans have condemned the attempted arson at the Indian consulate in San Francisco and called for expeditious action against those behind this "criminal act".

They also slammed the "violent rhetoric" against India's Ambassador to the US Taranjit Singh Sandhu and said free speech does not mean a license to incite violence or vandalise property.

A video by Khalistan supporters, dated July 2 and posted on Twitter, showed the act of arson at the Indian consulate in San Francisco.

The video, with the words "violence begets violence" emblazoned over it, also showed news articles related to the death of Canada-based Khalistan Tiger Force (KTF) chief Hardeep Singh Nijjar.

Nijjar, one of India's most-wanted terrorists who carried a cash reward of Rs 10 lakh on his head, was shot dead outside a gurdwara in Canada last month.

In a joint statement issued on Thursday, Congressmen Ro Khanna and Michael Waltz, co-chairs of the Congressional Caucus on India and Indian-Americans, said violence against diplomatic facilities will not be tolerated.

"As the co-chairs of the India Caucus, we strongly condemn the attempted arson and vandalism at the Indian Consulate in San Francisco and the posters circulating on social media with violent rhetoric aimed at Indian diplomats, including Ambassador Sandhu," they said.

"We support the right to free speech and freedom of expression for every American but that is not a license to vandalise property or incite violence. Violence against diplomatic facilities is a criminal offence and will not be tolerated. We urge the State Department to coordinate with law enforcement in their investigation of the damage at the Indian Consulate expeditiously and hold those involved accountable," they added.

Congressman Brian Fitzpatrick said the attack on the Indian consulate is unacceptable.

"I firmly condemn the repeated hateful attacks on the Indian Consulate and look forward to those involved being held accountable with appropriate legal action," he said.

Till Thursday, no action had been taken against those involved in the attack on the Indian consulate.

A spokesperson of the National Security Council of the White House said the US takes the safety and security of diplomats very seriously.

"We take very seriously the safety and security of diplomats living in the United States and strongly condemn acts of vandalism or violence against diplomatic facilities or personnel," the spokesperson told PTI.

Congressman Mike Lawler said the attempted arson at the Indian consulate was disturbing.

"I had the pleasure of welcoming Prime Minister (Narendra) Modi of India to Washington, D.C. last month and look forward to a continued, strong partnership with the world's largest democracy," he said.

Condemning the attack in the "strongest possible terms", Indian-American Congressman Shri Thanedar said, "Violence and attempts to instil terror are unacceptable in a democracy." Congressman Rich McCormick said this attack is vile and unacceptable.

"Americans stand by our allies and our patriotic Indian-American community," he said in a tweet.

Indian-American Congressman Ro Khanna slammed the posters against Indian diplomats in the US, including Sandhu, doing the rounds on social media.

"I know Ambassador Sandhu and respect him. When I bring up human rights issues, he always engages with civility, thoughtfulness & candor. This rhetoric puts diplomats in harm's way. It's dangerous and has no place in a democracy. Free speech does not mean a license to incite violence," Khanna said.

Last week's attack was the second time within months that the Indian Consulate in San Francisco was targeted by Khalistani supporters.

On March 19, a group of pro-Khalistan protesters attacked and damaged the consulate. Raising pro-Khalistan slogans, the protesters broke the makeshift security barriers raised by the city police and installed two so-called Khalistani flags inside the consulate premises. Two consulate personnel soon removed these flags.

In a tweet, the South Asian Minorities Collective said, "Known for their proximity to Pakistani intelligence service, the Khalistan cult has been trying to revive itself over the past few years in US, UK and Canada." Sikh leader Jasdeep Singh described the attack on the Indian consulate as "shameful and disgraceful".

"Whoever did it should be brought to the fullest extent of law. Targeting any consulate or any diplomat or anybody for that reason is not a good thing," Singh told PTI.

"Although it has not been identified who the perpetrators were, the community is very, very upset because it is being linked to the Khalistani movement.

"There is a line between freedom of speech and the right to protest and getting involved in criminal activities like this one. So, we strongly condemn this criminal act," he said.

Responding to a question, Singh urged the Biden administration to make sure that consulates and diplomats of all countries, especially India, are protected and safe in the US.

"The Sikh community by and large stands with the laws of this great nation, and if anyone breaks the laws of this nation, the government should go after them," he said.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.