Basically, 分 carries too many meanings so that it can be hardly understood by listeners when you just say 10分 but not 10分钟.
I mean, they may wrongly understand you.
我十分钟后回来。
Undoubtedly, you will come back in ten minutes.
我十分后回来.
Will you come back in ten minutes or , supposed now it's 6:03, will you come back after 6:10?