ISLAMABAD, Pakistan — Hundreds of Shiite women staged a sit-in in the western city of Quetta on Sunday evening to mourn the 84 people who were killed in an explosion a day earlier in a crowded market there, and they demanded that the government arrest the attackers.

Grieving relatives declined to bury their dead until the government promised to track down those responsible for carrying out brazen attacks against Hazaras, a Shiite ethnic minority, in the city.

Government officials said a team, led by a high-ranking police official, was investigating.

Protests and sit-ins were also held in other major cities on Sunday, as Shiite leaders condemned the government’s inability to curb the killings.

The attack on Saturday took place in Hazara Town, one of two enclaves in Quetta for Hazaras, who have suffered numerous attacks at the hands of Sunni death squads in recent years.