League Cup semis succumb to snow
The tie between Blackburn Rovers and Aston Villa, scheduled for Tuesday, and Wednesday's Manchester derby between City and United were called off because of dangerous travelling conditions across the north of England.
"The decision was taken in conjunction with the police match commander on the grounds of public safety," said a statement on Rovers website.
"It is snowing heavily in Blackburn, as it has been all morning, and advice locally is not to travel unless it is absolutely necessary."
United said on their website that the first leg at City's Eastlands ground had been rearranged for January 19 with the second leg now scheduled for January 27.
No new dates have yet been announced for the Rovers v Villa match.