Two Valley Stream South High School students were robbed at gunpoint on school grounds last week, police said Wednesday.

Nassau police said two teenagers from Rosedale, Queens, were arrested and a third suspect remains on the loose. Police did not disclose further details.

Valley Stream Superintendent Marc Bernstein said the two victims were returning from their lunch break on Friday when they were approached.

"It occurred on one of our very large playing fields, either the soccer field or the football field, which is on school property," Bernstein said. "The people wandered onto that and intercepted our kids."

Bernstein said the victims were within their rights to leave school grounds for lunch because it is an open campus. That policy will not change as a result of the robbery, he said.

Some students disputed the superintendent's description of where the incident occurred, saying it took place on a normally locked footbridge about 100 yards from the front entrance.