SHOPIAN, Kashmir — An Indian Army operation against militants fighting Indian rule in the Muslim-majority Kashmir Valley killed at least 12 militants on Sunday, the largest one-day death toll of insurgents in recent years, officials in Kashmir said.

At least three soldiers and four civilians also died, and about 70 other people were wounded in the army crackdown in the district of Shopian, according to the Kashmir authorities.

Army officials called the operation a major success. “It is a special day for our forces,” Lt. Gen. A. K. Bhatt said.

Kashmir — caught in a territorial dispute between Hindu-majority India, which controls much of the territory, and Muslim-majority Pakistan — has endured brutal conflict for decades.