CONCORD -- The California Highway Patrol shut down the Gregory Lane offramp of southbound Interstate 680 late Monday while Concord police searched for a suspect who ran from the car during a traffic stop, police said.

About 10:14 p.m., officers had just pulled over the vehicle on Contra Costa Boulevard near Crescent Drive, when the passenger in the car jumped out of the vehicle and ran, Concord police Lt. Darrell Graham said. Officers spotted the passenger throw what they thought to be methamphetamines from his window as the car pulled off the side of the road.

Officers later confirmed the items thrown to be the suspected drugs, Graham said.

The CHP shut down the offramp about 10:50 p.m. by request of the Concord police, Graham said. Officers, along with three canine units, searched for the man in that area for about 40 minutes before giving up the search.

The driver of the vehicle was arrested for drug possession and for possessing a hypodermic syringe. A second passenger was also arrested for possession of a syringe. The suspects have not been identified at this time.

"We have information regarding who the passenger might be," Graham said. "So we're going to go from there."

The Gregory Lane offramp reopened to traffic about 11:30 p.m., Graham said.

Contact Erin Ivie at eivie@bayareanewsgroup.com. Follow her at Twitter.com/erin_ivie.