At least 35 people were injured and shops were set on fire when the march coincided with with a sermon at a nearby Sunni mosque, the BBC reported Saturday.
Entrance and exit points to the city, near the capital Islamabad, were closed and security forces were patrolling the streets. Residents were ordered to stay home.
The curfew was set to expire at midnight Saturday, local time.
The procession was marking the anniversary of the death of Imam Hussein, the grandson of the prophet Mohammed, in the 7th century.
Eight persons were arrested in the violence, and mobile phone service was suspended, The News International reported.
Provincial officials said an investigation of the unrest has been ordered.