SINGAPORE - Many users of ride-hailing app Grab in Singapore, Indonesia, Thailand, the Philippines and Malaysia have faced intermittent disruption for the second day in a row on Wednesday (Nov 17), making it one of the worst service failures by the company.

Users reported all kinds of glitches from being unable to call for a ride or order food to drivers not being able to get bookings.

When contacted on Wednesday, a Grab spokesman in Singapore acknowledged the service disruption, saying it had "impacted a number of partners and users across the region".

In an updated statement later, the spokesman said that the disruption was caused when Grab tried to run a planned upgrade to one of its systems, which caused some services to be affected.

She said: "Our core services have been up and running since late Tuesday morning, and our users and partners have been able to use Grab services per normal. However, a small segment may still experience minor issues as we work on completing the upgrade."

In the statement, Grab apologised for the inconvenience, and added that it is in touch with its affected partners to provide support for them.

Delivery riders and consumers took to social media platforms to voice their complaints.

One of them, who wanted to be known only as Fan Xuan, said she had made an online purchase on Tuesday, but the transaction did not go through and she is now waiting for a $50 refund from Grab.

The 30-year-old also waited two hours for her food, had multiple drivers cancel on her and yet had no way to contact them.

A full-time Grab driver, Mr Jeevan John Menon, told The Straits Times that his earnings for Tuesday, which amounted to about $270, was not reflected in the app when he checked it last night.

When he cashed out his earnings this morning, the app showed that the process had been completed, but the amount was not reflected in his bank account.

He also tried to call the Grab hotline for drivers, but was put on hold for 20 minutes and did not manage to get any help.

Mr Menon said: "For riders who rely on Grab for a living, this can be very scary. I'm sure Grab is doing its best, but we need better communication to drivers especially when earnings are involved."

Others on social media said they had paid for food orders on the app but were not able to track or receive them.

When ST checked the app at noon on Wednesday, orders for food and rides could be placed, but the activity page was not able to load. An error message was reflected instead, informing users to refresh the app.

Grab operates in more than 400 cities in eight countries in South-east Asia, with millions of people relying on it for car and scooter rides as well as meal deliveries and digital financial services.

The service disruption comes weeks before Grab is preparing to merge with Altimeter Growth Corp, the United States special purpose acquisition company of Mr Brad Gerstner's Altimeter Capital Management.

Grab operates in a competitive space with keen rivalry from Gojek, which merged with e-commerce company PT Tokopedia.

Other rivals include Delivery Hero's Foodpanda and Deliveroo as well as new entrants such as AirAsia Group in the region.