The curfew was imposed from 9 PM tonight and would be in force till 6 AM on Friday.
Curfew, which had been imposed since yesterday, was relaxed for four hours each in two phases today during which two groups again came out to protest, prompting the District Collector to impose night curfew, they said.
It was imposed at Raisen when two groups had clashed over elopement of two Dalit girls with persons who belonged to a different community. Later, some Bajrang Dal workers created ruckus leading to tension in the town, official sources said.