Flags were lowered in the Pakistani city of Quetta --- as locals mourned the 81 people killed in a bombing the previous day.
Many Shi'ites are frustrated with the city's escalating violence --- and accuse the government of turning a blind eye to extemists.
There were similar demonstrations throughout the country.
In Karachi, around four hundred angry protesters set a bus and a water tanker on fire as they marched through the streets of the port city .
More than 400 Shi'ites were killed in Pakistan last year.
Protesters set fire to bus, water tanker in Pakistan (0:41)
Feb 17 - Shi'ites held protests across Pakistan after a Sunni group claimed responsibility for a bombing that killed 81 people in Quetta. Deborah Gembara reports. ( Transcript )