QUETTA, Pakistan (AP) _ Paramilitary police patrolled the dusty streets of Quetta, Pakistan on Sunday after riots between rival ethnic groups in the southwestern city.

Hundreds of protesters threw stones, smashed billboards and windows and forced shops to close for a second consecutive day on Sunday to protest the killing of five ethnic Hazaras by unidentified gunmen two days ago.

Eight other people were wounded in Friday's attack on a passenger bus on the outskirts of Quetta, the capital of southwestern Baluchistan province.

Hazaras blamed the killing on majority Pashtun and Baluch transport workers, who opposed drivers from the ethnic minority operating passenger vans on key routes. Hazaras, who are mostly Shiite Muslims, make up about 15 percent of Quetta's population.

Police in riot gear blocked main roads and fired tear gas shells on Sunday to stop hundreds of angry Hazaras from marching toward the city's center. The protesters attacked shops and burned vehicles while demanding the arrest of the killers.

On Saturday, protesters set ablaze and looted several shops and torched vehicles belonging to people from other ethnic groups. At least one person was killed and 20 injured in the rioting.

Police have arrested 41 people and were conducting raids to arrest other suspects in the rioting and killing, said Athar Hussain Sail, deputy commissioner of the city.

``We hope the situation will soon return to normal,'' he said.

Baluchistan is one of the poorest provinces of Pakistan, and feuds there between rival tribes and ethnic groups often run for generations. Rival Pashtun, Baluch and Hazara groups are heavily armed and often clash for dominance in the provincial capital, about 60 miles from Pakistan's southwestern frontier with war-battered Afghanistan.