Yes there are beggars, often they are young children waving a cup in front of you, we just said no thank you each time they asked and never had any problems. We had our sons aged 3 and 8 with us and they never got any hassle so I wouldn't worry too much.
I have also heard of the kids begging etc..My friend witnessed them with cups.He said a guy was in charge of him , but he just hid in the background.When the boy returned to the guy , with obviusly not enough money, my friend saw him beat the boy and sent him back again to beg for more.