Four people fell ill on the weekend after being exposed to an unknown substance on a North Surrey bus.
At 11:52 a.m. Sunday, Surrey RCMP was called to a bus near 96 Avenue and King George Boulevard.
The Coast Mountain bus was heading north on King George Boulevard, when a man smelling of a chlorine type substance boarded the bus.
He began crushing something up into a powder in the back, and passengers alerted the driver.
The driver went to the back and cleaned up the mess, as the man had gone.
About 15 minutes later, the bus driver fell ill, feeling like his nose was going to bleed.
Three passengers also felt ill.
The driver stopped the bus and called for assistance.
The fire department boarded the bus and found no evidence of a hazardous material.
"We don't know what it was and I guess we won't know what it was," said Transit Police spokesperson Anne Drennan. The bus has been thoroughly cleaned and will be brought back into service.
Anyone with information is encouraged to call Metro Vancouver Transit Police at (604) 515-8300.