According to the sources the blast happened at around 6:30 am local time in PD2, in Laghman Ada area of Jalalabad city.
An IED had reportedly been placed next to the road and was detonated when security force vehicles drove by.
One source said that 18 civilians were wounded along with three policemen.
According to the source, four of the wounded are in critical condition.
Provincial officials have not commented yet.
No group has claimed responsibility for the blast.