A group of Khalistan supporters gathered in front of the Indian Embassy here and many of their speakers tried to incite violence, but timely intervention by an alert US Secret Service and local police prevented a repeat of London and San Francisco incidents of vandalism at the mission.

Separatist Sikhs, who gathered outside the Indian Embassy in downtown Washington DC on Saturday, hurled abusive language and openly threatened Indian Ambassador to the US, Taranjit Singh Sandhu. The Ambassador was not in the embassy at the time of the protest.

Some of the speakers were seen inciting fellow protestors to indulge in violence and break the windows and glasses of the building across the road.

In their speeches, most of the protestors were seen trying to incite violence not only in India but here as well, including physical damage to the Indian Embassy property.

Sensing that things might go out of control, the Secret Service and the local police quickly brought in reinforcement and more forces were deployed in the area. At least three police vans were placed in front of the Embassy.

At one point of time, five protesters quickly crossed the road and were about to break into the temporary marker of the embassy property near the pole unfurling the tricolour before they were asked to leave.

Secret Service personnel, who were closely watching this, in no time rushed to the spot and asked the protesters to go back to the designated protest area, before any untoward incident could happen.

It appeared that the protesters had come prepared to do something similar like damaging Indian properties at the Indian Consulate in San Francisco and the Indian High Commission in London.

After the attack on the Indian consulate in San Francisco by pro-Khalistan protesters last Sunday, India had registered its “strong protest” with the US Charge d'Affaires in New Delhi over the incident and asked the American government to take appropriate measures to prevent the recurrence of such incidents.

During the protest by Khalistan supporters at the Indian Embassy in Washington, this PTI reporter saw separatists bringing two bundles of wooden sticks that were kept in the park that has the statue of Mahatma Gandhi in front of the embassy.

The wooden sticks were similar to those which were used to break the door and windows and smash the glasses of the Indian Consulate in San Francisco. While one bundle was used to display the separatist flag, the other bundle of about 20 sticks was kept aside.

Organisers of the protest had a very hostile approach towards the Indian reporter covering the protest.

They not only obstructed this reporter by coming in front of the camera and placing the Khalistan flag on his face, kept pushing him, but also threatened dire consequences.

The reporter, apprehending physical harm, called 911 and ran towards the other side of the road for safety, looking for a police van.

One of the protesters abused the reporter and was asking questions like you have to tell me what are you going to report? The organiser backed off as the reporter complained to the police about the potentially harmful activities of the protesters.

Sometime later, two of the protesters came towards the reporters, who were standing near the Secret Service personnel. One of them told the Secret Service that the reporter be asked to leave “my land” which is federal property.

They warned that if there is any violence and the reporter is physically harmed, they should not be blamed for this. Immediately the other protestor hurled abuse against the reporter, used unparliamentary words, and moved the two Khalistan flags that he had in his hand in such a way that its sticks hit the reporter's left ear with a bang.

The Secret Service personnel asked the reporter if he was ok. The Secret Service warned the protester that this should not be repeated, and sought additional reinforcement from police personnel.

The law enforcement official told the protestors that this was public land, and the reporter was all within his right to stand there and cover their protest.

In their speeches, the protesters repeatedly pointed fingers towards the two reporters and used abusive words against them.

While they prevented the journalists from doing their work, a group of protesters filmed the reporter covering their protest, took pictures and asked provocative questions.

The separatists left the area around after 3 pm and one of them was seen keeping the bundle of wooden sticks in the trunk of the SUV.

The Indian Embassy here condemned the attack on the PTI reporter.

"We have seen disturbing visuals of a senior Indian journalist from the Press Trust of India being abused, threatened & assaulted physically while covering the so-called ‘Khalistan protest’ in Washington DC earlier today," the Indian mission said in a statement.

"We understand that the journalist was first verbally intimidated, then physically assaulted, and fearing for his personal safety and well-being, had to call in law enforcement agencies, who responded promptly," the statement said.

The mission said it condemns such a grave and unwarranted attack on a senior journalist.

"Such activities only underscore the violent and anti-social tendencies of the so-called ‘Khalistani protestors’ and their supporters, who routinely engage in wanton violence and vandalism," it said.

It thanked the law enforcement agencies for their prompt response in the matter.

"This violence against @lalitkjha is outrageous and an assault on journalism. I condemn it in the strongest terms. Lalit is one of the fairest and most thoughtful journalists. Thank you to our security for protecting Lalit and the diplomats and consulate," Indian-American Congressman Ro Khanna tweeted.

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