The incident happened early Monday in the provincial capital Mehtarlam when a roadside IED was detonated as Governor Rahmatullah Yaramal drove by.
Provincial officials confirmed the incident and said Yaramal sustained only slight injuries.
A spokesman for the Laghman governor, Asadullah Dawlatzai, said seven people had been injured and eight killed.
He said among the dead were four security force members and four civilians, adding that most of the wounded were civilians.
Tariq Arian, spokesman for the Ministry of Interior, said the four security force members killed had been Yaramal’s bodyguards.