The Hazara community has long been targeted by the Islamic State and other militant Sunni groups, who see them as a heretical sect
Four Pakistani paramilitary guards were killed Sunday when a suicide bomber on a motorbike blew himself up in the southwestern city of Quetta, police said.
The bomber targeted Frontier Constabulary guards in the Mian Ghundi neighbourhood of the city -- around 140 kilometers (87 miles) from the frontier with Afghanistan -- where Hazara Shia merchants were trading vegetables.
Three died immediately in the blast, with another officer dying later of his wounds, said Azhar Akram, a deputy inspector general of police.
Akram told AFP that 17 guards and two civilians were wounded in the blast. Three are in a critical condition, he said.
A spokesman for the police's Counter-Terrorism Department confirmed the attack.
Quetta is home to approximately 500,000 Hazaras, who mostly live in an ethnic enclave on the edge of the city.
The community has long been targeted by the Islamic State and other militant Sunni groups, who see them as a heretical sect.
A series of bombings carried out by a Pakistani sectarian militant group in 2013 killed over 200 Hazaras in the city.
Frontier guards have also been targeted by Baloch insurgents, who have been waging a simmering insurgency for greater autonomy.