Three members of a family were killed and 11 others seriously injured after an improvised explosive device (IED) went off in Afghanistan southern province of Helmand, an official said Sunday.

The incident took place on Sunday afternoon in Shamalan area of Garmsir district of the province, where a man was making the IED supposed to attack the Afghan security forces.

The explosive was detonated prematurely, leaving the man, one of his sons and brother dead, and 11 of his family members including seven children and four women seriously injured, provincial governor's spokesman Omar Zwak told Xinhua.

The wounded, some of them in critical condition, were taken to a local healthcare center, the spokesman added.

Finding and neutralizing IEDs have been a challenge for the Afghan security forces.