At least a dozen people – most of them security personnel – were killed in a blast that targeted the bus of the Balochistan Constabulary on the outskirts of the provincial capital of Quetta on Thursday morning.

Police said 100 kilos of explosive material was used in the attack and was packed inside an auto-rickshaw parked nearby. It was triggered with a remote controlled device. The Tehreek-e-Taliban Pakistan (TTP) has claimed responsibility for the attack, according to Dawn.com.

Ahsanullah Ahsan, TTP spokesman, said the bus was attacked to avenge the killing of some of their men from Malakand in Balochistan. The attack comes days after Prime Minister-in-waiting Nawaz Sharif announced that his government would be open to peace talks with terrorists.