Islamabad: Militants on Tuesday stormed a bus carrying Shia Muslims in Balochistan province of southwest Pakistan, killing 13 men and injuring seven others in the latest string of attacks targeting the minority community.

Three gunmen travelling in a pick-up truck stopped the bus with about 30 passengers in Akhtarabad area on the outskirts of provincial capital Quetta, witnesses told the media.

Two gunmen entered the bus and fired indiscriminately, they said. Thirteen men, most of them Shia Hazaras, were killed and seven others injured, police said.

The injured were taken to the Bolan Medical Complex and those with critical wounds were shifted to Quetta’s military hospital. Officials described the condition of three of the injured as serious.

The attackers fled from the area before it was cordoned off by police and paramilitary Frontier Corps personnel.

City police chief Ahsan Mehboob removed a police officer from his post for failing to provide security to the bus in the wake of several attacks on vehicles carrying Shia Hazaras in Quetta and nearby areas.

A large number of Shia Hazaras reached the Bolan Medical Complex and staged a protest against the attack. The bus that was attacked was set on fire by angry protestors.

Some protestors shouted slogans against the police and the government for their failure to prevent attacks on Shias.

Some protestors accused the authorities of being in league with terrorists and demanded targeted operation and a crackdown on those who were attacking members of the Hazara community.

Witnesses said all the slain men were labourers who were going to a fruit and vegetable market for work. No group claimed responsibility for the attack.

The outlawed Lashkar-e-Jhangvi, a notorious sectarian group, has claimed responsibility for several recent attacks on Shia Hazaras in Balochistan.

Police said security has been stepped up at all exit points of Quetta to prevent the attackers fleeing the city.

Dozens of Hazaras, who stand out from the local population because of their distinct features, have been killed in attacks over the past few months.

Nearly 30 Hazaras were killed in attacks on a bus carrying Shia pilgrims and another vehicle near Quetta last month. Six more pilgrims were killed within Quetta city.

The pilgrims were heading to neighbouring Iran to visit shrines and sacred places.

The Shia Ulema Council, Hazara Democratic Party, Tahaffuz-e-Azadari Council and the local chapter of the Muttahida Qaumi Movement condemned Tuesday's attack.

The Shia Ulema Council called for three days of mourning.