Gunmen attacked the Ghazi Baba shrine overnight in Budhber, on the outskirts of Peshawar, and killed three caretakers.
"At least five militants attacked the shrine and opened indiscriminate fire, killing three caretakers," local police official Waris Khan said.
The incident came hours after a roadside bomb struck a school bus, killing one person and wounding two children in Peshawar.
There was no immediate claim of responsibility for the attack. Shrines across Pakistan have seen attacks during the last five years, with major shrines like Abdullah Shah Ghazi in Karachi and Data Darbar in Lahore being targeted in suicide bombings.