According to police, a Honda Pilot dropped off the suspects at the Gloucester Township Public Schools transportation center in Blackwood. Meanwhile, a white sedan circles the area, acting as a lookout.
Police say the suspects cut a hole in the fence around the bus yard and stole two catalytic converters.
The next night, they came back and stole four more.
Two other school buses were damaged by attempted thefts.
"It was a hardship with the schools," said Captain Jason Gittens. "Obviously, those buses had to be taken out of service. They had to put other buses in to go pick up the children for the day, there were thousands of dollars in damage caused to those buses to replace those catalytic converters."
Gloucester Township Schools Superintendent John Bilodeau called the crimes "annoying and frustrating," adding that transportation was not interrupted for students just after the thefts.
He said he and the school board will look at increasing security measures, including higher-quality surveillance cameras.
SEE ALSO: Washington Twp. police warn about rise in catalytic converter thefts
Last month, neighboring Washington Township put out a warning after several vehicles were hit in neighborhoods.
In September, Moorestown's school bus yard was struck by thieves. Nine catalytic converters were stolen from buses in that case.
The car parts contain precious metals that are worth thousands of dollars per ounce.
In New Jersey, a bill is making its way through the legislature that - if signed into law - would require sellers to provide the vehicle identification number and proof of vehicle ownership when selling catalytic converters for scrap.
Police are encouraging drivers to take precautions.
"They can install different cages along the catalytic converters or they can inscribe the serial numbers directly on the catalytic converters," said Gittens.
No arrests have been made in this case or the recent incidents in Washington Twp. and Moorestown.
Anyone with information should contact police.