12mo hitting other kids

My DD is 12m and she started doing this about a month ago. She goes up to other children on the playground and hits them with whatever she has in her hands or just slaps them. She is not doing this because she's malicious, I think she's just attracting my attention this way. She always looks at me when she does that, I come and take her away and she acts all happy. Do I continue to taking her away when she hits other babies or do I stop paying attention? How do I stop this behavior?