Police said the victims were approached in the area of Asilomar Drive and Larch Way by four suspects in two vehicles. One of the suspects pulled out a semi-automatic pistol and the suspects robbed the victims of money and personal belongings.
One of the victims was assaulted but neither sustained serious injuries, according to police.
A witness of the robbery was able to follow one of the suspect vehicles, contacting police and keeping an eye on the vehicle until officers arrived.
Antioch police officers conducted a traffic stop of the suspect vehicle on an onramp to state Highway 4 and detained 26-year-old Harold Wilson of Oakland and a 17-year-old Pittsburg resident.
Police said they also found items from the robbery in the vehicle but said the weapon was not found.
Police are still looking for two outstanding suspects. One was described as a black man in his 30s with light complexion, 5 feet 10 inches, 160 to 170 pounds. He was wearing blue jeans and a white T-shirt. The other suspect is a black man with dark complexion, between 25 and 30 years old, 6 feet 2 inches, 140 to 150 pounds and was wearing dark jeans and a white T-shirt.
The suspect vehicle was described as a late-model, four-door, small, bluish-gray car.
Anyone with information about the robbery should call Antioch police at (925) 778-2441.