Complex sentence: They stated that the family of the terrorists communicates with them and therefore had to be removed from dangerous areas, and that ISIL often uses civilians to plant car bombs or carry out other attacks on the YPG.
Split into simpler sentences: They stated that the family members of terrorists maintained communications with them and therefore had to be removed from areas where they might pose danger. They further stated that ISIL was using civilians in those areas to plant car bombs or carry out other attacks on the YPG.