How do you get dried in bloods stains out of towels?

I have dried in bloods stains on my towels, (a ladies day accident nuff said.) I can't get the stains out. I've tried soaking them in very cold water, Oxiclean which is good for some items, even hydrogen peroxide. Nothing seems to work. I can't use bleach because they are colored towels. By the way, I use ALL laundry detergent. Any suggestions?