Find rows containing N zeros in a matrix

I have a matrix like:

mat =[1 2 3;
      0 0 3;
      1 2 0;
      0 0 0;
      2 0 0];

To find a row full of zeros I do:

mat(all(mat==0,2)

 ans =

     0     0     0

What can I do to find the rows which only two zeros?

To get this:

 ans =

     0     0     3
     2     0     0

Answer 1

[Azzi Abdelmalek]

mat(sum(mat==0,2)==2,:)

For general case

N=2
out=mat(sum(mat==0,2)==N,:)

[Giorgos Papakonstantinou]

Thank you Azzi but this does not give me the rows which have 2 zeros. This gives me the rows which no zeros.

[Azzi Abdelmalek]

Look at edited answer

[Giorgos Papakonstantinou]

Thank you Azzi! Exactly what I wanted!