This is a movie that I watched back in the late 80's on cable
television. My vision of the movie is still pretty strong, but I never
found out the name of it. It was about a group of students in the
outback that were at a school and 4-5 masked gunmen show up with
shotguns and masks over their faces, they take these kids hostage
along with the teacher, have them get in a school bus and the gunmen
bury the bus in a large mine of some sort in the outback. Eventually
kids and teacher escape and go and find help at nearby homes only to
find out that the masked gunmen have taken over the home(s) they need
help from. Couple of old people who own the home get shot with a sawed
off shot gun and the kids do their best to escape again in the
outback. I remember the gunmen with MASKS over their face yelling out
the kids, we're gonna get you, etc... Finally, students set up a
series of trap that skewer the bad guys as they fall to their death on
sharpened poles. Have been wondering the name of this flick ever since
I watched it at the time. Anyone who could help, that would be great!!

I am confident that you are remembering a movie called "Fortress," in
which an Australian schoolteacher and several students are abducted
and terrorized by brutal masked criminals. The teacher and her young
charges turn the tables on the bad guys, as you've described.

Internet Movie Database: Fortress
http://imdb.com/title/tt0091069/

Here are some online descriptions to help verify that this is the correct movie:

"This movie is about a teacher (Rachel Ward) who gets abducted along
with her class by a group of men wearing various face masks. They are
taken into the outback and sealed in an underground cave. The teacher
and her students begin searching for a way out and discover they must
swim for their freedom. Once free, they once again become prisoner of
those who abducted them."

Amazon: Fortress (1985)
http://www.amazon.com/exec/obidos/tg/detail/-/B00000F3MC/104-8867107-6979939?v=glance

"Sally Jones and her class are looking forward to the few remaining
days to the end of term. Pleasant anticipation turns to stark horror
as four grotesquely masked men descend on Sally and the children and
whisk them away at gunpoint. A damp and dark cave becomes prison for
Sally and her nine young charges until they manage to grope their way
to freedom by way of an underwater exit. Their newfound freedom,
however, is short-lived as their captors are waiting for them at a
nearby farmhouse, where they have overpowered the old farmer and his
wife."

Crawfords Australia: Fortress
http://www.crawfords.com.au/libary/movie/fortress.shtml 

My Google search strategy:

Google Web Search: fortress "rachel ward" cave masks
://www.google.com/search?hl=en&q=fortress+%22rachel+ward%22+cave+masks

I hope this is the movie you're looking for. If it is not, please
request clarification; I'll be glad to offer further assistance before
you rate my answer.

Best regards,
pinkfreud

Sweet!!! I have been searching for over 10 years now and within a days
time I get the answer --- the power of the internet & google.. Thanks
so much!!!!!