(Bloomberg) -- Singapore’s immigration systems were largely back to normal after a disruption that caused delays at Changi airport and at land-border crossings just before the start of the weekend.

Although travelers were told to delay non-essential travel, there haven’t been any flight cancellations, according to data from Flightradar24.com. The glitch came two days after the city’s largest bank, DBS Group Holdings Ltd., suffered a 10-hour outage on its mobile-phone apps and online-banking. 

Singapore’s Immigration & Checkpoints Authority said technical issues led to the disruption.

“Preliminary investigations found that there was a technical glitch during a pre-scheduled system upgrade, and this caused an unanticipated system overload,” it said in a Facebook post Friday night.

Singapore prides itself on efficiency and being a trusted business hub. Rated the world’s top airport for the 12th time by Skytrax earlier this month, Changi handled 68.3 million passengers in 2019, before the Covid pandemic decimated the global travel industry. Known for its indoor waterfall, butterfly garden and plethora of shopping outlets, Changi has also embraced automation to handle the large volume of passengers passing through the Southeast Asian hub.

Earlier, off-duty immigration officers were called in to manually process departing passengers at Changi with all the automated lanes affected, the border authority said. A representative for Singapore Airlines Ltd. said flights are currently operating as scheduled.

Live images from a government website earlier showed dozens of cars lined up on Singapore’s Woodlands and Tuas checkpoints on its land border with Malaysia.

The system slowness added to wait times at land checkpoints which can see as many as 400,000 commuters each day to get to work as well as deliver produce across the Singapore-Malaysia causeway. Traffic tends to be heavier on Fridays as workers return home for the weekend.

At Changi, arriving flights were delayed by an average of 8 minutes impacting 31 flights, while departures were affected by an average of 31 minutes on 210 services, data from Flightradar24.com showed.

Changi doubled down on introducing contactless technology during the pandemic in a bid to smooth transit through the airport once travelers returned en-masse. Self check-in kiosks and baggage drops operate when a person hovers their finger over a screen.

Passengers use automated immigration gates that scan faces and irises if those biometrics are registered in a passport.

--With assistance from Nurin Sofia.

(Adds reason for the disruption in third paragraph. A previous version of this story corrected the attribution on the advisory to avoid non-essential travel.)

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