One person was killed and three others sustained injuries as a roadside bomb went off in southern Helmand province, a former Taliban stronghold on Saturday, a press release of provincial government released here Sunday said.

"The tragic incident happened in Mir Mandab area of Gereshk district yesterday afternoon leaving one civilian dead and three others injured," the press release added.

Blaming Taliban militants for organizing the bomb attack, the press release added that the blast occurred close to a police van but inflicted casualties on civilians. The police sustained no injuries.

Taliban militants who are largely relying on suicide and roadside bombings, haven't yet made comment.