Hamilton businesses on both sides of the Waikato River lost their internet connection after a fibre cable was severed in Hamilton East.
The outage has been attributed to workers carrying out excavation work on the Hamilton Ring Road project.
Ultrafast Fibre Ltd operations general manager William Hamilton said staff were working to restore internet access to all users by late afternoon.
''Some Hamilton residents and businesses experienced an internet outage at approximately 10.30am this morning.
This was a result of a road working contractor accidentally cutting through one of the main Ultrafast Fibre (UFF) cables on the corner of Ruakura and Peachgrove Roads,'' Mr Hamilton said.
''The road works are part of the major road network upgrades currently taking in place in Hamilton. UFF are working to restore internet access to those affected and this should be completed by 4pm today.''
Wintec communications director Erin Andersen said their city and Rotokauri campuses were affected by the outage.
The outage had affected staff and students' emails, the staff intranet, printing facilities and their student database.
Their phone system was also affected.
Ms Anderson said all classes had gone ahead as scheduled and student enrolments were still being taken.
''It's a traditionally quiet time of year for us,'' she said.
All services were restored by 3.45pm.
Waikato Regional Council's BUSIT and Waikato Civil Defence websites also were also affected by the outage but were back online early this afternoon.
Hamilton Central Business Association general manager Sandy Turner said she had not heard of any businesses losing their Eftpos facilities.
''I've been out and about quite a bit today so if there was a widespread problem like that I'm sure I would have heard people talking about it,'' she said.