MUMBAI: Maharashtra chief minister Uddhav Thackeray on Tuesday tried to reassure migrant workers who are stranded in the state that lockdown is not "lock-up", and appealed them to face the "challenge" of coronavirus by staying back.He was speaking in a live webcast after hundreds of migrant workers gathered near Bandra railway station here, seeking to head back home, even as country-wide lockdown was extended till May 3.The chief minister spoke briefly in Hindi as he made a direct appeal to the migrants.Thackeray also said his government was working on how to lift the lockdown and resume industrial activities.Rising number of cases in Mumbai and Pune was a cause of concern, he admitted.Maharashtra has conducted maximum number of coronavirus tests and has asked the Centre to allow experimental plasma treatment, he said.