Trains at Mumbai's Lokmanya Tilak Terminus were seen packed with migrant workers.
Migrants were leaving the financial capital as they feared an impending lockdown.
This comes amid a steep rise in the number of Covid-19 cases across Maharashtra.
“This train will go to Gorakhpur, we're leaving due to the surge in Covid-19 cases,” a migrant said.
Congress leader Sanjay Nirupam has, meanwhile, asked authorities to allay migrants' fear.
Mumbai's BMC on Thursday imposed a weekend lockdown in the city until further orders.
Maharashtra reported 56,286 fresh Covid cases and 376 deaths in the last 24 hours.