Four members of the Hazara minority died Monday in a sectarian attack in the western city of Quetta, a senior Pakistani police officer said.

The four Hazaras - a Central Asian people who practice Shi'ite Islam - had just closed their shop in the Masjid neighborhood when they were shot to death by unknown gunmen, police deputy inspector general Fayyaz Sumbal told Dawn newspaper.

Pakistani Prime Minister Nawaz Sharif "energetically" condemned the attack and expressed solidarity with the families of the victims.

Sectarian attacks, especially against Shi'ites, who make up 20 percent of Pakistan's population, have increased over the past year amid a general resurgence of violence since late 2012.

Thirty people were killed last month in a bombing at a Shi'ite prayer center in Quetta's Hazara Town, while more than 250 Shi'ites died early this year in attacks in Karachi and Quetta.

Sectarian violence claimed 537 lives in Pakistan last year, according to the Pakistani Institute for Peace Studies. EFE