The NCR agitation, called by All India Gujjar Mahasabha, is in support of the community's demand for Scheduled Tribe status in Rajasthan where 39 people were killed last week in clashes between the police and protestors.
A protest march was held at Mayur Vihar in east Delhi this morning while protestors blocked traffic on Mehrauli- Gurgaon road, Noida Express Highway and NH-24 besides stopping a passenger train in Loni area of adjoining Ghaziabad.
There were reports that agitators pelted stones at police personnel at Aya Nagar in south Delhi but there was no official confirmation.
Anticipating blockades, Railways cancelled ten trains, including Nizamuddin-Kochi, Maharashtra Sampark Kranti, Nizamuddin-Udaipur and Dehradun-Bandra Express.
Sources said over 35,000 police personnel, including those from the central paramilitary forces, were deployed in Delhi and surrounding areas, particularly in Gujjar strongholds in the region.
The Union Home Ministry had put the National Capital Region on high alert two days ago following the agitation call and issued advisories to Delhi, Haryana and Uttar Pradesh governments asking them to take all measures for maintaining peace.
Home Secretary Madhukar Gupta, who is personally monitoring the situation, is in touch with the Directors General of Police of Uttar Pradesh and Haryana, and the Police Commissioner of Delhi. Gupta has asked the three police chiefs to keep utmost vigil in the vulnerable areas.
Police are keeping a strict vigil on Delhi borders -- especially on three points, Aya Nagar, Bopari and one in north-east district -- to keep trouble-makers at bay.
A senior Delhi police official said there were specific intelligence inputs that the Gujjar protestors will try to block traffic in many areas.
"The community has a sizeable population in South and East districts. We anticipate more troubles in these areas and along the inter-state roads," he said.
Security personnel were deployed in strength in Gujjar strongholds like Mehrauli, Ghazipur, Patparganj, Badarpur, Khanpur, Ayanagar, Chilla village and Rampur, anticipating a strong showing by the community during the agitation.
Local policemen and paramilitary personnel were also deployed in adjoining Faridabad, Gurgaon (both in Haryana), Noida and Ghaziabad (both in Uttar Pradesh).
There was an unusual rush on certain stretches in Delhi as office-goers chose to leave for office early anticipating traffic snarls in the later part of the day.
A traffic policeman on duty said there were more vehicles on roads this morning before the rush hour.
"I did not want to take a risk. You don't know how things unfold. I have an important meeting at my office which I could not afford to miss. So I left early," Shanker Roy, who works in a financial firm in Delhi's Connaught Place, said.