Islamabad, Pakistan (CNN) -- Unknown gunmen killed 11 people Saturday in an attack on Shia Muslims in southwest Pakistan, police said.
A local passenger van was transporting Shia Muslim passengers in the outskirts of Quetta when two gunmen opened fire, said Nazir Ahmed, a senior police official in the city, which is the capital of Balochistan province.
"It was clearly sectarian violence," Ahmed said.
Balochistan has long been plagued by sectarian violence between Sunnis and Shias, and separatist Baloch militant groups who demand political autonomy.
The attack comes a day after at least seven people were killed and eight others injured in Quetta, police said.
In the Friday attack, militants on two motorcycles opened fire on a group of people in the city, said Fareedullah Bareech, superintendent of police.
Bareech said the victims were waiting for a bus bound for Iran from Quetta when they were attacked.
"This was an act of sectarian terrorism," Bareech said. He said the assailants fled.
Journalist Syed Ali Shah contributed to this report.