LONDON – Households in England's second city, Birmingham, are being urged to stop socializing with others from Friday as part of a dramatic tightening of coronavirus restrictions in the wake of a sharp spike in new confirmed cases.Amid mounting evidence of a pick-up in transmission rates across the U.K., the mayor of the West Midlands, Andy Street, said tougher restrictions on household mixing in Birmingham, and the nearby boroughs of Solihull and Sandwell, were necessary in light of a big local increase in virus cases.Though the ban formally comes into effect on Tuesday, Street advised affected residents "to avoid household mixing before then as it has been identified as one of the drivers of transmission.”Street said younger people have.