Kolkata, July 7 : The Mamata Banerjee-led West Bengal government on Tuesday decided to impose complete lockdown in all the designated Covid-19 containment zones across the state from July 9. According to sources in the state secretariat Nabanna, the new restrictions will be imposed in all the containment zones from 5 p.m. on July 9. No business activities would be allowed in the containment zones, so that the spike in the number of fresh Covid-19 cases can be checked. All government and non-government offices would remain closed. There will be strict restrictions on public movements in all the market areas that fall under the containment zones and isolation units. Only emergency services will be kept out of the total lockdown purview. Wearing a mask is also mandatory before stepping out of homes. "Wear a mask whenever in public. Mask is a must," Kolkata Police Commissioner Anuj Sharma tweeted. There are at least 18 containment zones and 1,872 isolation units in Kolkata. At least 10 more containment zones were added to the existing list on Tuesday evening. Total lockdown will also be imposed in Malda's 49 municipal wards from Wednesday to handle the rise in new Covid-19 cases in the district. /IANS