Farmers' tractor rally against the contentious agricultural laws on Republic Day was "infiltrated by anti-social elements", the protesters' body Samyukt Kisan Morcha said in a statement this evening, hours after thousands of demonstrators clashed with policemen in different parts of Delhi. Protesters were tear-gassed and baton-charged shortly after they pushed down barricades at the borders this morning and stormed into the heart of the city amid celebrations for 72nd Republic Day.