I'm afraid so. They are omniverous and will take young birds / mammals etc if they can. Where I used to live - village in Yorkshire near a big sheep farm - the farmer told me that bigger crows used to even attack newborn lambs.
I live near a big pond and last summer my boyfriend saw a crow pick up a duckling and carry it away, it dropped it on the path then the mother ducks came running at the crow and saved the chick!
Crows are opportunistic and will attack even large animals like sheep and try to peck their eyes out. If the sheep can't get out of the way quite often the crows suceed, too. Tongues and under the tail are also vulnerable regions.
I had the unfortunate opportunity of watching crows lifting baby pigeons out of their nest high up in my lime tree on one occasion. I felt so helpless - but nature can be so cruel.
Apparently the Crows used to be content with going through the rubbish bins in the park but since the council installed bins with lids, food has become more scarce so that partly exaplains the fact that this year they have overtaken the foxes in thier murdering ways ..... ;-(