SEATTLE -- A driver pulled a gun on another driver during a road rage incident on Interstate 90 in Seattle Friday morning, the Washington State Patrol said.

The victim called 911 to report the driver of a 2004 Volvo S60 pulled a black semi-automatic pistol out of a holster and pointed it toward the rear of his vehicle as the two were heading eastbound on I-90 just west of the Mount Baker tunnel, troopers said.

The victim ducked and quickly changed lanes, and later lost sight of the gunman's vehicle, troopers said.

Troopers spotted the gunman's car in Bellevue, where they took the man into custody. They found a loaded black semi-automatic pistol, holster and six extra rounds of .380 caliber bullets in the man's vehicle, the State Patrol said.

Troopers said the victim may have inadvertently cut off the gunman as he was merging from southbound I-5 to eastbound I-90, triggering incident.

The gunman is a 21-year-old Seattle man, troopers said.