Thousands of north Queensland residents within a tropical cyclone warning zone were without telecommunications services for hours after suspected copper thieves cut cables.

Providers say some mobile and internet services were affected for residents in the Townsville suburbs of Mt Low, Bluewater, Black River, Toolakea and Saunders Beach after fibre cables at a mobile site were cut.

A Telstra spokesperson said mobile services are now back online in Mt Low, Bluewater, Black River and Saunders Beach after technicians removed over 7 kilometres of damaged fibre by hand in two locations in tough weather conditions.

Technicians are still working to restore remaining services as quickly as possible.

Townsville residents have been told to take shelter after the Bureau of Meteorology declared Tropical Cyclone Koji off the north Queensland coast and has forecast the category two storm will make landfall mid to late Sunday morning.

A couple stand at a doorway

Townsville father and daughter Bill and Kylie Poulsen have been impacted by the outage. (ABC News: Baz Ruddick)

Optus said in a statement that the outages were caused by “an act of vandalism, which resulted in a significant break” at the Mt Low mobile site, which is also used by Telstra and the National Broadband Network.

Telstra regional general manager Rachel Cliffe said crews were working to bring services back online and any calls to Triple Zero (000) would automatically divert to any available mobile network.

Toolakea Beach residents Kylie and Bill Poulsen said they had been preparing for the potential cyclone, but noticed that their internet was out at about 9:30pm Friday.

“We’re as ready as we can be, if we can find out what’s going on, which is a bit of a problem with what’s going on with the communications down,” Ms Poulsen said.

Cyclone map

Cyclone Koji is expected to make landfall on Sunday.  (Supplied: Bureau of Meteorology )

She said it was disappointing that communications had been impacted during severe weather, and those with medical conditions also relied on the internet.

“Filthy grubs that are doing this stuff, we are fairly hardened to this because it happens so often. We’re absolutely over it,” Ms Poulsen said.

“These fools that are doing it, just go away, stop.”

Ms Poulsen, who has prepared for many cyclones, said having access to updates on social media was important.

“It’s an issue when we’re in an event like this,” she said.

‘You can’t get a lower act’

While police have launched an investigation, Premier David Crisafulli condemned what he said was a “low act”.

“Somebody has cut those telecommunications lines while trying to steal copper,” Mr Crisafulli said.

“My message to that low-life is that you have at risk the lives of north Queenslanders in their hour of need and you can’t get a lower act than that.”

David Crisafulli speaking

David Crisafulli says telecommunications are critically important. (ABC News)

He said telecommunications were critically important during natural disasters.

“We intend to throw the book at this individual when they are caught because it’s a low act at anytime, but during a disaster that’s about as low as you can get.”

Townsville Mayor Nick Dametto said up to 5,000 residents could be affected.

“This puts the community in a position, when important messaging needs to get out in the midst of a natural disaster, we’re unable to do that or we have a limited ability to do so,” Cr Dametto said.

Queensland warnings and information.

In an emergency phone Triple Zero

“What’s happened in the northern suburbs overnight is very disappointing … it’s the most un-Australian kind of thing that could happen.

“Stealing something, if that’s what’s happened, in the middle of a natural disaster is something that no-one should be proud of.”

Cr Dametto said technicians were doing the best they could to restore services.

He urged all Townsville residents to prepare for the severe weather expected in coming days.

“We do remind people, go back to your cyclone kit, go back to your emergency kit, make sure your radio is in there … and make sure you’ve got plenty of batteries to keep up to date.”