They set the fields afire near Nongtrai village probably in retaliation to the villagers' appointing guards to prevent theft of produce from the fields, village secretary Ksan Pilat Wahlang told PTI.
The incident took place on Sunday the gang took advantage of the absence of the guards as they had gone to church and destroyed the crops worth Rs 10 lakh, Wahlang said.
The fields spread over nearly two square km belonged to Nongtrai village headman B Lyngdoh and six others, he said adding the affected area is within 2 km inside border fence.
The police conducted an inquiry yesterday after an FIR was lodged with them on Tuesday.
East Khasi Hills district administrator Sanjay Goyal said he is awaiting a report from the police after which follow up action will be taken.
The crop theft had earlier been reported to the BSF and they had carried out an inspection, Wahlang said.