Police have issued a warning to Trafford Centre to shoppers to wear a face covering - or receive a fine.The Greater Manchester Police team in Stretford said they had officers in the shopping centre yesterday, and will be back again on Sunday.So far five tickets have been issued to people who did not have a covering and could not present valid exemption.The fine is now £200 for a first offence, reduced to £100 if paid within 14 days.The government has also warned that repeat offenders receiving