R: generating random points using csr

I have a polygon map of Mozambique, along with administrative districts. I'd like to generate 10 random points within each district. I am using R's csr function, but it isn't working:

for (f in Mozambique$NAME_1){
    Points=csr(f,10)
}

I keep getting the error "Error in poly[, 1] : incorrect number of dimensions". What should I do to diagnose and fix this problem?