Gunmen attacked a bus carrying Shia Muslims in southwest Pakistan, killing 13 people in the second major sectarian attack to hit the area in two weeks.
Pakistan has faced mounting criticism from its minority Shia community and human rights groups for failing to prevent thousands of sectarian murders.
The drive-by shooting happened on the outskirts of Quetta, the capital of Baluchistan, which borders Iran and Afghanistan.
The Shias were members of Pakistan's minority Hazara ethnic group and had been travelling to Quetta when four gunmen attacked the bus.
Television footage showed the bus engulfed in flames, with blood and passengers' luggage seen scattered at the site sealed off by a paramilitary and police cordon.
Up to 400 people demonstrated outside the Bolan Medical Complex where the wounded were taken for treatment, condemning the government for inaction over sectarian groups.
Baluchistan has become an increasing flashpoint for sectarian violence between Pakistan's majority Sunni Muslims and minority Shia, who account for around a fifth of the country's 167m population.
On 20 September, gunmen killed 26 Shia pilgrims after ordering them off their bus in Mastung, a district 50km south of Quetta.
It was the deadliest attack on Shias in Pakistan since 4 September 2010 when a suicide bomber killed at least 57 people at a rally in Quetta.
Gunmen then killed another three Shias on the outskirts of the city who were going to collect the bodies of relatives who died in the first incident.
