AWS automatically keep on creating ECS instance.

I was playing with ECS service and ended up deleting all services and related clusters. But in ec2 dashboard, as soon as I kill instances like "ECS Instance - EC2ContainerService-default-8f8f5fd5-dbfc-4f81-843a-c028e86a1657" it creates another instance. Do any one have pointers how can I disable this automatic build.