NEW DELHI, Feb. 6 (Xinhua) -- Indian authorities sounded an alert and beefed up security in the national capital New Delhi Saturday ahead of farmers' call for chakka jam (roadblock).

The protesting farmers have called for a three-hour nationwide blockade of state and national highways against the three controversial agricultural laws.

However, emergency and essential services such as ambulances and school buses will not be stopped during the roadblock.

According to the farmers, the chakka jam, which will begin from 12:00 noon to 3:00 p.m. (local time) will not affect the national capital city.

Officials, in a bid to avoid the violence and chaos that they had witnessed last month during farmers' tractor parade, have deployed thousands of police personnel and kept a strict vigil in the city.

Reports said around 50,000 personnel of the police, paramilitary and reserve forces are standing guard at various key points of Delhi and the national capital region.

The farmers have been protesting for over two months at borders of Delhi, demanding a complete repeal of the three controversial farm laws.