The top US diplomat said several Pakistani soldiers also died in the blast involving an improvised explosive device (IED).
“Just this morning I woke to the news that we have lost two local employees in Peshawar who worked with our consulate there who were going out on an effort to eradicate narcotics fields,” Kerry said at an event.
“An IED exploded and several were lost. A few of the soldiers who were there to guard them also,” he added, without going into more specifics.
The State Department did not immediately provide more information on the incident.
Peshawar, located in northwest Pakistan, made somber global headlines in December 2014 when the Taliban massacred more than 150 people there, mostly children, prompting the country’s army to intensify its offensive against militants.