Professor Jason Leitch told BBC Breakfast: "About 20 per cent of our cases link back to that kind of pub and hospitality sector. "Remember, the final thing about the risk here is pubs and hospitality, even mitigated, are more risky than other places because they have an exemption for the distancing so they are allowed to be at one metre distancing and you are allowed to go with two households; so, even mitigated, they are more risky than you in your home just with your own household." First Minister Nicola Sturgeon announced the Scottish government has toughened coronavirus restrictions further in a bid to slow the spread of the virus during her daily briefing on Wednesday, 7 October. All pubs and restaurants in the central belt will have to close, both indoors and outdoors, from 6pm on Friday. The stricter restrictions will apply in the Greater Glasgow and Clyde, Lanarkshire, Ayrshire and Arran, Lothian and Forth Valley health board areas and are set to affect about 3.4 million people living in the central belt. Asked what will happen if there is no change after the 16 days for which the restrictions on licensed premises have been put in place, Leitch added: "I'm very hopeful that something will change, that the numbers will begin to move. "Now, remember, this virus isn't norovirus, you don't know you've got it tomorrow and you're sick - it takes seven to 10 to 14 days to show, so we are not going to be completely out of the woods at 16 days. "But the earlier restrictions that we've had in households, in other places in the last few weeks, the work we've done in student halls, those restrictions are beginning to show their effect. "Another three weeks from now, two-and-a-half weeks from now, I'm hopeful that the numbers will have begun to fall, and we're going to do work in this time to just check the guidance, check the mitigations are as strong as they can be, talk to the stakeholder groups, the sectors, make sure we're doing everything we can to allow them to open safely." Pubs, bars, restaurants and cafes across other parts of the country are not allowed to serve alcohol indoors from Friday and can only open between 6am and 6pm for food and non-alcoholic drinks. But liscenced premises in the central belt can continue to serve alcohol outdoors until the 10pm curfew which is still in place across the UK and was introduced last month. Alcohol can still be served at weddings and funerals which are limited to a maximum of 20 people and can only take place in regulated premises. The rule still applies that a maximum of six people from two households can meet together in hospitality venues, either indoors or outdoors. Reporting contributed by PA. A message from the Editor: Thank you for reading this story on our website. While I have your attention, I also have an important request to make of you. The dramatic events of 2020 are having a major impact on many of our advertisers - and consequently the revenue we receive. We are now more reliant than ever on you taking out a digital subscription to support our journalism. Subscribe to scotsman.com and enjoy unlimited access to Scottish news and information online and on our app. Visit https://www.scotsman.com/subscriptions now to sign up. By supporting us, we are able to support you in providing trusted, fact-checked content for this website. Joy Yates Editorial Director