India's consulate in San Francisco came under an attack from Khalistan supporters who tried to set the diplomatic facility on fire in the second such act of violence within months, drawing strong condemnation from the US government which termed it a "criminal offence".

A video by Khalistan supporters, dated July 2 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.

Responding to the incident, State Department spokesperson Matthew Miller in a tweet on Monday said: “The US strongly condemns the reported vandalism and attempted arson against the Indian Consulate in San Francisco on Saturday. Vandalism or violence against diplomatic facilities or foreign diplomats in the US is a criminal offence.”

Diya TV, a South Asian broadcast TV network in the US, said in a tweet that “a fire was set early Sunday morning between 1:30-2:30 am in the San Francisco Indian Consulate."

"The fire was suppressed quickly by the San Francisco Department, the damage was limited and no staffers were harmed. Local, state and federal authorities have been notified,” it said.

The outlet also posted a video of the arson attack.

A poster being shared on social media says that a "Khalistan Freedom Rally" will be organised on July 8 that will start in Berkeley, California and end at the Indian embassy in San Francisco.

This is the second time within months that the Indian Consulate in San Francisco came under attack from Khalistani supporters.

On March 19, a group of pro-Khalistan protesters attacked and damaged the Indian Consulate in San Francisco. Raising pro-Khalistan slogans, the protesters broke open 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.

Ajay Bhutoria, an Indian community leader, said the attack on India's consulate in San Francisco is extremely concerning and must be condemned in the strongest possible terms.

"It is deeply disturbing to see such acts of violence targeting diplomatic missions," he said.

"The Indian consulate serves as an essential hub for providing consular services and fostering bilateral relations between India and the United States. It is crucial that the staff and members of the consulate are able to operate in a safe and secure environment, free from any threat or harm," he added.

Bhutoria asked the San Francisco Police Department to swiftly investigate the incident and bring the perpetrators to justice.

"Ensuring the safety and security of diplomatic missions is not only a responsibility of the host country but also a fundamental obligation under international law," he said.

It is imperative that such incidents are met with a strong response from the authorities to deter any further attacks and ensure the safety of diplomatic personnel, he said.

"Let us stand united against violence and work towards promoting peace, understanding, and harmonious relations," Bhutoria said.

External Affairs Minister S Jaishankar on Monday said India has asked its partner countries such as Canada, the UK and the US not to give space to "extremist Khalistani ideology" as it is "not good" for relations.

He was responding to reports of Khalistani posters in Canada naming senior Indian diplomats.

The minister said the issue will be raised with the government of that country.

The "radical, extremist Khalistani ideology" is not good for India or its partner countries such as the US, Canada, the UK and Australia, he told reporters on the sidelines of a BJP outreach campaign.

"We have already requested our partner countries like Canada, the US, the UK and Australia where sometimes Khalistani activities happen, not to give space to Khalistanis. Because their (Khalistanis) radical, extremist thinking is neither good for us nor for them nor our relations," the minister said.

"We will raise the issue of posters with those governments," Jaishankar said.