ISLAMABAD, Pakistan — At least 16 people were killed when a powerful bomb ripped through a vegetable market in Quetta in southwestern Pakistan early Friday, officials said. At least nine of the dead were Hazaras, a Shiite Muslim minority group that has repeatedly been the target of Sunni extremists.

There was no immediate claim of responsibility for the attack, which also injured at least 30 people, some of them critically. But Lashkar-e-Jhangvi, a banned militant Sunni group, has often carried out attacks against Hazaras in Quetta, the capital of Baluchistan Province.

For years, the Hazaras have lived in a state of perpetual fear in Quetta, and promises made by successive governments have failed to ensure their safety.

While terrorist attacks have declined significantly in the past year across the country, the attack on Friday was a grim reminder that the Hazaras continue to remain vulnerable to militant violence and that the security provided to them remains inadequate. Quetta has a large presence of security forces and a vast network of intelligence operatives.