Farmers agitation entered its fourth day on Friday, with protesting farmers facing tear gas at the Punjab-Haryana Shambhu Border, as security forces tried to disperse them. This comes after the third round of negotiations between Punjab Chief Minister Bhagwant Mann, the heads of the farmer unions and Union ministers Piyush Goyal, Arjun Munda, and Nityanand Rai concluded in the early hours of Friday.

Tear gas shelling took place for 15 minutes at the Punjab-Haryana Shambhu border.

The shells were logged near the stage of protestors, from where they have been addressing the protestors. Our reporter on ground said several youths were setting gunny bags ablaze and throwing them towards the security personnel. This is what reportedly led to the firing of tear gas shells.

The Delhi Police has ordered more than 30,000 teargas shells from the Border Security Force's (BSF) Tear Smoke unit, officials said.

Police and paramilitary personnel kept a tight vigil on the activities at the borders of the national capital.

An officer said strict vigil, heavy deployment of personnel and multi-layer barricades will remain in place as the protesting farmers are still sitting at the Shambhu border between Punjab and Haryana, near Ambala.

The Delhi Police, along with the paramilitary personnel, conducted drills and mock exercises where they were asked to move towards the barricades in anti-riot gear at the Singhu and Tikri borders. They were ordered by their seniors to act as if they were controlling a mob.

Due to the closure of the border points, the locals faced challenges while going for work. The forces also dug up the narrow lanes, so that the farmers could not use those to enter Delhi.

At the Tikri border, the local businessmen put up banners requesting the protesting farmers to "let our businesses run for our families".

Board exams, however, were held without any hassle and no delay was reported in the conduct of the examination at the border areas of Delhi. Vehicles were arranged by the police and paramilitary officials to help students reach the exam centres near the Tikri border.

A senior police officer said in the wake of a "Bharat Bandh" call given by the Samyukta Kisan Morcha (SKM) in support of the protesting farmers, the force is on high alert.

Security personnel remained deployed at a third border point -- Ghazipur. In the evening, a group of 50 farmers from Meerut arrived in their cars. They were detained by the Uttar Pradesh Police as they wanted to stage a sit-in at the Ghazipur border.

The Delhi Police has set up a multi-layered barricade with cement blocks, barbed wires and nails in two lanes on the flyover at the Ghazipur border. However, the other lanes were open for commuters.

The Delhi Police has ordered more than 30,000 teargas shells from the BSF's Tear Smoke unit located at Tekanpur in Madhya Pradesh's Gwalior, officials said, adding that this is being done as the police wants to stock up more tear gas shells.

Some trains on the Delhi-Amritsar route were diverted after farmers squatted on railway tracks at many places in Punjab over the Haryana Police's action against the "Delhi Chalo" protesters.

Farmers also staged dharnas at several toll plazas and forced authorities not to charge commuters a toll fee.

Bharatiya Kisan Union (Ekta Ugrahan) and BKU Dakunda (Dhaner) had given a call for a four-hour "rail roko" protest at several places in Punjab.