QUETTA, Pakistan — Calligraphers linger at the gates of an ancient graveyard in this brooding city in western Pakistan, charged with a macabre and increasingly in-demand task: inscribing the tombstones of the latest victims of the sectarian death squads that openly roam these streets.

For at least a year now, Sunni extremist gunmen have been methodically attacking members of the Hazara community, a Persian-speaking Shiite minority that emigrated here from Afghanistan more than a century ago. The killers strike with chilling abandon, apparently fearless of the law: shop owners are gunned down at their counters, students as they play cricket, pilgrims dragged from buses and executed on the roadside.

The latest victim, a mechanic named Hussain Ali, was killed Wednesday, shot inside his workshop. He joined the list of more than 100 Hazaras who have been killed this year, many in broad daylight. As often as not, the gunmen do not even bother to cover their faces.

The bloodshed is part of a wider surge in sectarian violence across Pakistan in which at least 375 Shiites have died this year — the worst toll since the 1990s, human rights workers say. But as their graveyard fills, Hazaras say the mystery lies not in the identity of their attackers, who are well known, but in a simpler question: why the Pakistani state cannot — or will not — protect them.