My daughter and her friend do not get along.?

My daughter and her friend do not get along but love to play together. They whole time they are togther though they nic pick at everything. SO I asked do ya'll even like to play together and they said yes. I told them if the fighting cont. Then they would not be allowed to play they are only 5 years old so the fights are...stop looking at me and she stuck her tongue out or fighting over a toy then hitting each other to get the toy, talking at the same time. I am lost and don't know what to do for them to get along because they always want to play together.