Killer Klowns from Outer Space

When a small town is invaded by aliens from outer space who are capturing and killing the townspeople, no one takes them seriously. Why? The aliens all look like circus clowns, use weapons that look clown like, and all have painted on smiles. Only a few of the young people in the town realize the danger and of course no one believes them. Armed with an ice cream truck they try and rescue their friends.