NEW DELHI: PM Narendra Modi served notice of a lengthy battle against Covid-19 and more measures to contain and isolate its spread when he thanked people for responding to his call to observe a ‘ janata curfew ’ and signal empathy with frontline workers by clapping, ringing bells or banging ‘thalis’ for five minutes at 5 pm on Sunday.He emphasised his call for social distancing and stay-at-home advice through multiple tweets as he urged people not to start celebrating the end of ‘janata curfew’ and instead asked them to gear up for a long battle that could only be won if people stayed united and committed.Modi tweeted, “Today’s janata curfew may get over at 9 pm but that doesn’t mean we should start celebrating. Do not consider it a success. This is the beginning of a long fight. Today, countrymen have declared that we are capable, if we decide, we can beat the biggest challenge together.”His comments came on a day when the Centre announced that some 80-odd districts were being placed under lockdown to break the chain of transmission of coronavirus . In another tweet, Modi urged people in districts where a lockdown has been announced to stay at home and ensure they remain safe and ensure the safety of their neighbourhoods.“Follow instructions being issued by the central government and state governments. In districts and states where lockdown is announced, do not leave houses at all. Those in other parts of the country, do not get out of houses unless it is very necessary,” he tweeted.