India’s Election Commission cut off campaigning early in the eastern state of West Bengal after days of clashes in the final stretch of the country’s marathon elections, a drastic and unprecedented action in the world’s largest democracy.

The three-member body said in the order on Thursday that “growing incidents of disruption and violence” were creating a “fear psychosis” among voters, and ordered campaigning to cease by 10pm on Thursday, a day before it had been scheduled to end.

Normally campaigns run up to 48 hours before polls open, according to Indian law.

On Tuesday, rival political supporters fought with sticks and rocks during a rally for India’s ruling Bharatiya Janata Party, which is trying to wrest seats from Trinamool Congress, a powerful regional party that currently governs West Bengal.

Violence was also reported in the state during last Sunday’s polls.

The commission is invoking for the first time Article 324 of the Indian Constitution, which gives it superseding powers over India’s Parliament and state lawmakers to conduct free and fair elections.

“But it may not be the last in cases of repetition of lawlessness and violence,” Chandra Bhushan Kumar, a deputy election commissioner, told reporters Wednesday.

Nine parliamentary constituencies vote Sunday in the seventh and last round of India’s staggered, weeks-long national election, which has been a highly acrimonious campaign that has seen Prime Minister Narendra Modi blame opposition parties for the country’s ills.

Both Modi and Mamata Banerjee, West Bengal’s chief minister, were holding last-minute campaign events Thursday.