School teacher and her young schoolchildren on the run from men with masks possible kidnappers, one is wearing a pig mask for sure, they hide in a cave at one point in the film, I believe it was based in Australia not sure possibly in the 80's

All I had to do was Google keywords from your question --

Amazon.com: Fortress: Rachel Ward, Arch Nicholson: Movies & TV (http://www.amazon.com/Fortress-Rachel-Ward/dp/B000GAKDP6/ref=cm_cr_pr_product_top)

http://www.imdb.com/title/tt0091069/