That would be zabierają or porywają.
Zabierają would be the most general translation of take, including both benign and sinister meanings.
Porywają means kidnap.
Brać kogoś/coś na ręce - (lit. to take sb/sth on hands) - to pick someone/something up. The difference between this and 'podnieść kogoś/coś' (to pick up sb/sth) is that you usually hold this somebody/something in your hands.
Also - brać na wycieczkę - to take on a trip. This sentence is not that dark :)
It doesn't change to accusative case here? In Russian it changes to naszych dietiej from naszy dieti.
It is accusative
In Polish plural not masculine personal nouns have accusative=nominative
also singular masculine not animated and neuter nouns have accusative=nominative
so N dziecko= A dziecko, N dzieci=A dzieci
They first thing that came to my mind was something about those child services.
the ones translated to brać, zabierać