Toddlers and pinching

[kellogg06]

DS will be 3 in two weeks. My H picked him up from daycare today and his teacher said he's been pinching other kids a lot. So much so that other parents have complained about him by name and kids won't play with him. We went through a pinching phase a few months ago when he transitioned to the preschool room. He was the youngest and still learning to communicate. He got a lot better until now. What can I do to stop this pinching thing?