Protests turned violent in parts of Jammu city so much so that curfew had to be imposed.
It was said that mobs attacked some people and burnt vehicles following the terror attack in Pulwama in Jammu and Kashmir.
The terror attack resulted in martyrdom of as many as 40 security personnel making it worst terrorist act in recent times.
Over a dozen people have been injured in mob attacks, sources said.
Two army columns have been sent to stage flag march and maintain peace, officials said.
The curfew was imposed as authorities feared a communal backlash, they added.
Protesters, particularly in the old city, refused to disperse even after loudspeakers announced that curfew was imposed.
There was a complete shutdown in Jammu city, with no traffic on roads and all shops and markets closed.
Several areas of Jammu were hit by massive anti-Pakistan protests with people taking to the streets, including Jewel Chowk, Purani Mundi, Rehari,
Shaktinagar, Pacca Danga, Janipur, Gandhinagar and Bakshinagar.