EAST GREENBUSH — Authorities closed a stretch of Interstate 90 outside of Albany Saturday after police said a man riding in a taxicab opened fire on a state trooper during a traffic stop.

Witnesses described a chaotic scene as a large contingent of state and local police responded to the area in East Greenbush at around noon. The unidentified man was arrested and taken to an area hospital with gunshot wounds, where he was reportedly on life support Saturday evening.

State police weren’t providing details about the incident, except to say that the man was shot and in police custody.

Rensselaer County District Attorney Richard McNally told the Albany Times Union that a county SWAT team that was training nearby where the incident occurred shot the man, who had fled from the cab into the woods

I-90 was closed in both directions between exits 10 and 11 into Saturday evening as police continued their investigation.

No police were shot.

One driver said what started with a traffic delay turned into terrified motorists and passengers fleeing from the gunfire. Some backed up, others crossed the snowy medium to go in the other direction and others left their vehicles and ran, he said.

The driver told the Times Union he was stuck in traffic when heard the shots and thought police might have been euthanizing a bear. Then he saw people starting to get out of their cars.

Devin McKeon, who was returning from the Berkshires with his wife, told the paper they heard “a volley of shots” and then saw people running.

“It was pretty frightening,” he said.

AP-ES-01-10-09 1834EST