Thirteen people were killed and 14 others wounded in separate attacks in the southern Afghan province of Helmand, said authorities on Saturday. Five members of the National Directorate for Security (NDS), or the intelligence agency, and one policeman were killed when their patrol was hit by an Improvised Explosive Device (IED) overnight in Helmand\'s Sangin district, an NDS source told Xinhua. On Friday evening, four people, including a policeman, were killed and five others injured when an IED targeted a police van in a main square of the Marja district, the provincial government spokesman Omar Zawak told Xinhua. Also in Sangin, one woman was killed and eight children were wounded as a mortar round fired during an engagement between Taliban and security forces struck a house on Friday, Zawak said. Two policemen were killed and one was injured in a grenade attack in provincial capital Laghkar Gah, 555 km south of Kabul late Friday. The Taliban has intensified attacks since they launched annual spring offensive in April. Helmand has been notorious for growing poppy and the Taliban hotbed.