More than 400 bus drivers walked out of depots and joined picket lines in Oxford - in the first of two strikes - causing disruption for passengers across the city.
The Oxford Bus Company is warning passengers that they will face "significant disruption" during two days of planned strikes.
The Company said it had been unable to reach a settlement with the Unite union in a dispute over drivers' pay for the Christmas 2016 period.
Union members will strike on Thursday 2nd March and Monday 6th March.
The bus company is advising its passengers to make alternative travel arrangements.
Oxford Bus Company: disruption due to the weather. City4C buses will not serve Dean Court, instead running along the ring road and Eynsham Road, stopping outside Dean Court Estate facing towards Oxford.