May 24 update: B.C.'s police watchdog found no wrongdoing in the case.

A distraught man walked into a McDonald's in East Vancouver Thursday night and lit himself and parts of the restaurant on fire, according to police.

Witnesses said the man walked into the McDonald's near Commercial Drive and East Broadway with a gasoline can and started pouring fuel on the floor.

"It started gathering under people's feet who were in the McDonald's," one woman told reporters at the scene. "They got freaked out, obviously, (and) evacuated."

The man, who is in his 30s, also allegedly threatened to harm himself. Police were called to the scene and tried to negotiate with him, but said they were unable to stop the man from igniting himself.

Firefighters said a blaze also erupted in the rear of the fast food restaurant, but was quickly put out.

"A fireball did occur in the back of the McDonald's," Battalion Chief Brian Bertuzzi said. "Our crews did an excellent job knocking the flames down and prevented it from extending to neighbouring buildings."

Police fired less-lethal ARWEN rounds at the man, and fire crews doused him with a water hose. He was then taken to hospital with serious burns.

B.C.'s police watchdog, the Independent Investigations Office, confirmed it was later called to investigate what happened.

The IIO is dispatched anytime someone is killed or seriously hurt during an encounter with police, and "does not require any allegation of wrongdoing," the civilian body said in a news release.

Anyone with information on the incident is asked to call the IIO's information line at 1-855-446-8477.

With files from CTV Vancouver's Nafeesa Karim