When Does Mother Cat Leave Her Kittens?

Hi, I have just found 2 very loud lil kittens in a hole (home I think) however, one keeps climbing out and crawling around the sidewalk.  I don't think they are much  older than 2 weeks.... Have they been stranded or will the mother be close by? (I can´t see her) I am worried as there are many cats and the males kill the kittens.

Any suggestions... ??? Are they stranded or is mother just left them for a while (been 40 mins)

thanks

About 2 weeks

The first 2 weeks the mother will stay with her kittens except the eat and use the bathroom. When the kittens are older she will stay away from the kittens for longer period of times