Some SingTel users have reported problems with the service provider's mobile network on Wednesday.
Users said they were experiencing problems with the 3G network at different areas of the island including Jurong, Serangoon, Bedok, Punggol and Orchard.
SingTel in a statement said that some customers experienced intermittent difficulties with mobile access at 11.05am. This was due to a technical glitch.
It added that a backup server was automatically activated and customers were advised to restart their mobile phones.
"Our fully redundant system restored itself and all data services were normalised within 20 minutes. Voice and SMS services continued to operate normally during this time," it said.
The network issue comes after customers of service provider M1 encountered intermittent services for voice calls and text messaging on Tuesday morning. The issue was resolved after six hours.