Schools and colleges in some parts of the city declared a holiday, but government offices, the stock exchange, and banks remained open as rains lashed Mumbai for a fourth straight day.

Weather officials forecast heavy to very heavy monsoon rains in the city and its surroundings over the next two days and urged people to stay indoors.

A spokesman for Mumbai International Airport said flights in and out of India’s second-busiest airport were delayed.

Flooded railway tracks forced authorities to cancel more than a dozen long-distance trains, while suburban trains, a lifeline for the city’s population of about 18 million, were also affected, railway officials said.

Thousands of passengers were stranded at railway stations and others were forced to walk home through waist-deep water on rail tracks.

“Disaster management cell and all concerned departments are working hard to provide every possible assistance to Mumbaikars,” Devendra Fadnavis, the chief minister of the western state of Maharashtra, where Mumbai is located, said in a Twitter message.

Although Mumbai bills itself as a global financial hub, many parts of the city struggle to cope with water-logging during the annual monsoon rains.

Floods in 2005 killed more than 500 people in the city. The majority of deaths occurred in shanty town slums, which are home to more than half of Mumbai’s population.

Unabated construction on floodplains and coastal areas, as well as storm-water drains and waterways clogged by plastic garbage, have made the city increasingly vulnerable to storms.