Eleven trainee Pakistani police officers have been shot dead in what is believed to have been a sectarian attack in the capital of Balochistan province, Quetta.
Distraught relatives identified victims' bodies at Quetta hospital
Another nine are reported to have been wounded in the attack, carried out by two men on a motorcycle.
No group has said it was behind the killing - the second in a week targeting members of the minority Shia community.
The Inspector General of Police in Balochistan Shoeb Suddle, told the BBC's Urdu service that it might have been the work of a banned Sunni militant organisation, Lashkar-e-Jhangvi.
Thousands of people have been killed in violence blamed on militants from the country's Sunni and Shia communities since the late 1980s.
The incident is reported to have happened near the city's fruit market.
"Two men came riding on a motorbike and opened fire with a Kalashnikov at the vehicle carrying the police recruits to their school at 1600 (1100 GMT)," police officer Raja Ishtiaq told AFP news agency.
"We were returning to police training school from our homes after spending the weekend, and suddenly two men came on a motorbike and open fire on our vehicle," AFP quoted one of the survivors, M. Ali, as saying from hospital.
He said he believed it was a sectarian attack "because we all are [Shia] and ethnic Hazaras".
Police have fanned out across the city, setting up checkpoints. The governor and chief minister of Balochistan visited the hospital where the injured were being treated and promised the culprits would be found.
Last Friday, two armed men riding on a motorbike sprayed bullets at Shia activist Syed Niaz Hussain Shah, 50, as he was returning home from his office in the city. A week earlier, a Shia trader was also killed.
Over the past decade, there have been hundreds of sectarian attacks in Pakistan, in which thousands of people have been killed. Many have been in Karachi, where the greatest number of Shias live.
In April, Pakistani police arrested Shabir Ahmed, a suspected member of Lashkar-e-Jhangvi which has been linked to the killings of both Shia Muslims and Christians.
The group has also been accused of having connections with Osama Bin Laden's al-Qaeda network in Afghanistan.