“What the fuck”

I was in the U-bahn station Rosenthaler Platz, Friday at 13:25, waiting for the Ubahn. I was standing near the wall, and two kids (around 10-12 years old; both smaller in size than me – I am 1.60m) passed by, walking very near to me. The first passing next to me very near, made a strange face looking at me – as if he was trying to intimidate me – while going on his toes to reach my height. Then the second one passed near me and made the gesture of trying to put a piece of paper – that he had in his hand – into my tshirt (i had a sleveless top), but fortunately he didn’t touch me because i moved away his arm with my hand. I looked at them shocked and said “What the fuck” (I wasn’t able to think in that moment, nor speak German). They walked next to other girls sitting and one put his hand on a girl’s shoulder, so she also protested. A man who assisted to the scene came by and with a deep voice said “alles gut?!” to make them go away.