WASHINGTON (Reuters) - Two local employees of the U.S. consulate in the Pakistani city of Peshawar and some soldiers were killed by an explosive device while on drug-eradication mission, U.S. Secretary of State John Kerry said on Tuesday.

“Just this morning, I woke to the news that we had lost two local employees in Peshawar who worked with our consulate there who were going out on a effort to eradicate narcotics fields,” Kerry told an event in Washington on countering violent extremism.

“An IED exploded and several were lost; a few of the soldiers who were there to guard them also,” Kerry said.

State Department spokesman John Kirby said the incident occurred on Tuesday when the two Pakistani employees were traveling in a Pakistani government Anti-Narcotics Force convoy in Ambar tehsil, in the Mohmand Agency of Pakistan’s Federally Administered Tribal Areas (FATA).

“The U.S. government strongly condemns the attack,” Kirby said, adding that the United States was offering its assistance to Pakistan in investigating the incident and bringing the perpetrators to justice.

Kirby said he said not know whether the consulate employees were the targets of the attack, which came during a visit to the United States by Pakistan’s national security adviser Sartaj Aziz.

“Nobody has claimed responsibility at this point,” Kirby told a regular news briefing.

“We don’t know how premeditated or planned this was, and we certainly don’t have additional information about the specific targets, we’re going to have just keep working at this.”