According to the police, the curfew was imposed in Katghar, Manjhola and Galshaeed areas where several people were also injured in the violence.
Special Director General of Police Brijlal told PTI, "Members of the two communities who are these days observing Roza and taking part in Shravan mela clashed with each other leading to tension."
Rapid Action Force, police and Provincial Armed Constabulary have been deployed in affected areas and more force is being summoned from neighbouring districts, Brijlal said, adding the situation was tense but under control.
The city has been witnessing communal tension since Saturday night when a group of 'kanwarias' set afire some vehicles and pelted stones at a factory unit where people were offering Ramzan prayers.
The 'kanwarias' apparently got angry when their procession route was changed.