I'm not an expert on bugs but this reminds me of something I encountered. I see some potting mix on the sides of the container. Did you recently pot them or transplant them? What did you use? I had mail ordered a bag of organic potting mix that was infested with fungus gnats. From what I read this is not an uncommon thing to find.
Yours look very similar to the fungus gnat larvae I saw. Mine were mostly on the potting mix but a few did venture onto the grass I was growing in a container. I was recording a time lapse video at the time. You can check it out on my blog to see if they look the same at the following link:
I used neem oil, which in this instance acts much like the soap solution kevinsky proposed. It's something I usually have on hand for dealing with insects and plant disease.
The larval stage of a few bugs look like what's in your picture. It may be something else but I thought I'd throw this out there in case it helps.