I have people starting horrible hurtful rumours and threatening me over facebook! Can a charge them for haras?

Slander? Defo of character? Please help! My partner commit suicide 20 months ago and they are saying i killed him saying things about my children threatening to kill and hurt me! Telling all the pol from my small home town lies!! Ppl say ignore it but it just keeps going! They have started groups about me on facebook I'm nearly at breaking point!