A tent was damaged as a fire broke out at the farmers' protest site on the Delhi's Singhu border on Saturday, police said.
No loss of life was reported in this incident, a police official said.
However, the Sanyukt Kisan Morcha, an umbrella body of farmer unions spearheading the stir against the Centre's farm laws, said two tents were damaged in the incident.
However, the spirit of the farmers is unaffected, the body said.
Meanwhile, Jamhuri Kisan Sabha general secretary Kulwant Singh said no person was injured in the incident but things were damaged.
Sukhwinder Singh, a protester, suspected that it was someone's doing.
Rain stopped around 5 pm and the fire in the first tent broke out around 5.30 pm. Later, another tent, which was around 100 metres away, caught fire. We suspect that someone has come here and done this thing, he said.
Farmers have been camping at Delhi borders since November last year, demanding the repeal of the Centre's three contentious farm laws and a new law to guarantee minimum support price for crops.
However, the government has maintained that the laws are pro-farmer. Several rounds of talks between farmers and the government have failed to break the deadlock over the farm laws.