In the first four months of the year the number fell by 8.9 percent year-on-year, the city said in a report.

"The development of services like Grab, Go-Viet and Be has increased competition for buses, attracting passengers who travel short distances. These services are flexible and priced competitively."

A bus ticket costs VND5,000-6,000 (21-26 cents). But a Go-Viet motorbike ride costs less than VND5,000 (21 cents) for short distances when there are promotions while a GrabBike for two kilometers costs only VND12,000 (51 cents) after discounts.

Homegrown FastGo offers a VND25,000 ($1) taxi ride for five kilometers while Singapore app TADA offers VND20,000-50,000 ($0.86-2.14) discounts on rides.

Last year the city's Department of Transport said ride-hailing motorbikes had affected revenues of bus companies after the number of passengers fell by 3 percent to 571 million to miss the year’s target by 10 percent.

Seven bus routes were discontinued due to heavy losses, it added.

Saigonbus, a major operator with 500 buses, raised concerns in its 2018 annual report. "Ride-hailing services are drawing away a large number of customers from public transport with regular promotions."

The company reported a loss of VND 37 billion ($1.6 million).

Its board targets pretax revenues of VND14.4 billion ($617,700) this year.