The Ahmedabad MunicipalCorporation (AMC) on Friday ordered closure of paan shops in the city to discourage spitting in public spaces, a habit, officials believe, is responsible for spreading coronavirus.Seven people have tested positive for coronavirus in Gujarat so far.Although the AMC has already imposed a ban on spitting with a penalty of Rs 500 for violators, it did not prove to be a deterrent for people who chewed tobacco or paan and spat in public spaces, AMC commissioner Vijay Nehra said."The ban on spitting was imposed four days ago and we have caught at least 4,500 violators and collected fines to the tune of Rs 20 lakh," he said.However, this penalty wasn't enough, which is why the civic body decided to shut paan shops till March 31, he added.Grocery stores selling packets of paan masala will also face closure if they don't stop the sale, he said.City buses, BRTS will not run during the 'janata' curfew and public parks and gardens, including Sabarmati riverfront, will remain shut for the day, Nehra said."We have decided to shut clubs, party plots and gymnasiums till March 31. AMC-run Aadhaar enrollment centres as well as city civic centres will also remain closed during this time," the civic body chief said.At least 559 passengers were screened at Ahmedabad International Airport on Thursday night, and of these, four showed symptoms of coronavirus, he said."Four passengers were hospitalised for further procedures and 63, who came under high-risk category, were shifted to the AMC's quarantine facility, Nehra said.Others were adviced 'home quarantine', he said, adding that around 450 persons are under 'home quarantine' in Ahmedabad at present.Seven persons, who were asked to undergo 14-day 'home quarantine' upon their arrival earlier, were caught roaming around by AMC teams and sent to Sola Civil Hospital with the help of police.