Nazir Ahmed, a senior teacher, was gunned down by men riding a motorcycle on Arbab Karam Khan Road in Quetta, the capital of Balochistan province.
The gunmen escaped after the attack. The motive behind the attack could not immediately be ascertained.
Angry students protested against the killing, blocking roads and destroying public property. Police briefly detained some students following the protest.
No group claimed responsibility for the killing.
Balochistan has been rocked by ethnic and sectarian violence that has claimed scores of lives in the past few months.
