Teachers in some schools across Singapore were unable to boot up or connect their computers to their schools' Wi-Fi networks on Monday afternoon.

The Ministry of Education (MOE) told The Straits Times yesterday that it was a technical issue.

MOE chief information officer Tan Bee Teck said: "Once alerted, MOE investigated the case and confirmed that it was due to a glitch in the device configuration system, and thus ascertained that it was not a cyber-security incident."

He added that the issue was resolved as of 3pm on Monday.

Several teachers, who declined to be named, took to Facebook that afternoon to share that their Internet access was down.

HardwareZone, a website for technology-related discussions and updates, said the glitch began at around noon.

"Some teachers... faced an issue of not being able to log in on their work laptops. A pop-up appears with a sad face," wrote one user, crediting a source who was on the staff at one of the schools affected.

MOE said about 5 per cent of users across 234 schools were affected.

Mr Tan said: "MOE is working with schools to get the affected devices' system configuration updated."