Although service providers remained tight-lipped about suspension of the mobile Internet services, a senior police official said the step was taken to check spreading of rumours.
Services were unavailable to subscribers in Kupwara, Baramulla, Bandipora and Ganderbal districts on Thursday morning.
Residents of Srinagar and south Kashmir also said they were unable to access mobile Internet services in the morning.
Officials said the suspension was a temporary measure and services would be restored as soon as the situation returns to normal.
Four civilians were killed during clashes between stone pelting mobs and security forces in north Kashmir's Kupwara district since Tuesday.
The trouble erupted after locals alleged that a soldier had tried to molest a school girl in Handwara town on Tuesday.