SAN FRANCISCO » A busy stretch of a San Francisco Bay area freeway turned into a commuter’s nightmare Wednesday after a gunman barricaded himself inside a nearby hotel room and fired a shot toward the road, authorities said.

The incident led the California Highway Patrol to briefly stop traffic at about 11 a.m. on a section of Interstate 580 that includes the Richmond-San Rafael Bridge. The bridge reopened shortly after noon along with eastbound lanes of the freeway.

But the standoff continued late Wednesday night as police negotiated with the gunman, who also is a suspect in a stabbing Sunday at a supermarket in San Rafael. The man, whose name has not been released, was believed to be inside the hotel room with his girlfriend.

"We’re attempting to bring this to a safe resolution," San Rafael police spokeswoman Margo Rohrbacher said. "No one has been injured thus far and we hope to keep it that way."

SWAT teams and dozens of officers from various agencies were at the hotel, with police negotiators in "constant contact" with the gunman, Rohrbacher said.

But traffic was being diverted around the hotel, with a section of the interstate closed between U.S. Highway 101 and Sir Francis Drake Boulevard, according to the California Highway Patrol.

"All the traffic that is planning to use eastbound 580 has to come down to a focal point at the Sir Francis Drake onramp, so there’s not much we can do to get around that," CHP officer Chris Rardin told KTVU-TV.

With no estimated time for the road to reopen, authorities were recommending drivers avoid the area.

The standoff began after officers went to the hotel room while investigating the supermarket stabbing. The situation escalated when the man barricaded himself in the room and told police he was with his girlfriend and had a gun, Rohrbacher said.

A shot was then fired from the window of the room.

"The shot that he fired went toward the freeway," CHP Sgt. Trent Cross said. "Bullets can be unpredictable, so we wanted to be sure no one was harmed while driving by. So we shut down the bridge and the freeway."

Police said a man had taken groceries from the supermarket and left without paying. He was brought back inside the store for questioning before he threatened an employee and allegedly held a knife to the person’s throat.

The suspect ran out of the store with several employees in pursuit, and a clerk was stabbed in the chest, Rohrbacher said. Previously, someone had tried to stab a worker in the meat section.

The clerk’s injuries were not serious, Rohrbacher said.