People in the areas of the Northern Territory hardest hit by Cyclone Lam say they were not ready for the storm and are struggling to cope in the aftermath.

Don Wininbea cleaning up a tree which just missed his house in Galiwinku, on Elcho Island. ( ABC News: Steven Schubert )

Disaster response crews have reached small communities along the Arnhem Land coast that felt the full force of the category 4 system as it made landfall in darkness on Friday night.

Chief Minister Adam Giles said there were just two reports of injuries from Elcho Island following the cyclone.

"A 12-year-old boy, who we believe has a fractured arm, not as a result of the cyclone, and a nine-year-old child also in Galiwinku, who has an electrical burn," Mr Giles said, while announcing emergency financial assistance would be made available to those affected.

Both children have been evacuated to Royal Darwin Hospital.

But two community health workers on the ground at Galiwinku, on Elcho Island, told the ABC they were worried about the impact of trauma on their community.

Mental health worker Charlie Yebarrarr for many people in the community this was the first cyclone they experienced.

"The damage is really bad and it's the first one a cyclone had gone through here," he said.

"Trauma is a main issue. People are not coping with their trauma."

His colleague Johnny Dhurrkay said the health of those who lived in the cyclone-affected areas would be an issue in coming days.

"We don't have any toilets, we don't have any showers and we don't have any power," Mr Dhurrkay said.

Non-Indigenous residents said the community was not prepared.

A communication tower down in Galiwinku, on Elcho Island, NT, after Cyclone Lam passed directly over. ( ABC News: Steven Schubert )

"There were no official communications leading up to it," Grace Tongatua said.

"There was no real time to get ready. I didn't feel it was well organised."

Resident Don Wininbea's house was in good condition after a near miss, with a huge tree down in his yard.

He was outside on Saturday morning chopping it up with an axe.

He joined other locals in saying the community did not get sufficient warning.

"We didn't know when the cyclone was coming through," Mr Wininbea said.

"There were still young boys running around."

But Mr Wininbea said the community would recover from the disaster.

"We have some strong people here and that will help," he said.

In Darwin to officially open an abattoir, Prime Minister Tony Abbott said emergency financial assistance would be made available.

Some of the damage caused by Cyclone Lam at Galiwinku, in remote northeast NT. ( ABC News: Steven Schubert )

Individuals and families will have access to immediate relief payments of up to $495 per adult and $250 per child, up to a maximum of $1,245 per family.

Financial assistance for essential repairs to homes and the replacement of household and personal items would also be made available to eligible individuals and families.

Local shires can also receive financial assistance to help with the costs of repairing essential public infrastructure damaged by the effects of the cyclone.

The Arnhem Land Progress Association donated $100,000 to four affected communities - Milingimbi, Gapuwiak, Galiwinku and Milingimbi.

The aid will be distributed in $50 vouchers for individuals.

The association owns one of the shops in Galiwinku.

The decision came about in part because many people were not able to use their BasicsCard due to EFTPOS systems not working.

The BasicsCard is used to quarantine welfare payments in the NT.

Inland communities spared the worst

Authorities were monitoring rainfall levels around the town of Katherine, a regional hub 300 kilometres south of Darwin, but the town appears to have been spared.

The community of Beswick, about 92 kilometres from Katherine, experienced minor flooding.

Commander David Proctor said with the immediate threat of Cyclone Lam now passed, authorities were turning to the safe restoration of essential services and maintaining the health and safety of residents.

Trees stripped of their foliage after Cyclone Lam pass over Elcho Island. ( ABC News: Mike Donnelly )

He said Cyclone Lam caused significant damage to buildings and infrastructure at Galiwinku, on Elcho Island, with some damage to infrastructure at the coastal communities of Milingimbi and Ramingining.

Commander Proctor said people evacuated from the path of the cyclone last week would be returned to their communities over the coming days.

He warned people in cyclone-hit areas to beware of flooded roads, downed trees and live power lines.

Schools at Nhulunbuy, Yirrkala and Maningrida are set to reopen Monday, with a decision around opening other Arnhem schools to be made in the coming days.

A state of emergency was declared in communities including Milingimbi, Ramingining, Galiwinku, Gapuwiyak and Mapuru Outstation.

The Minister for Police, Fire and Emergency Services, Peter Chandler, said he had taken that step to "re-establish the normal pattern of life for residents and communities affected by Cyclone Lam".

'We need support'

When the ABC visited Milingimbi on Friday afternoon after the cyclone had passed, residents said the emergency response had not yet arrived.

There were no police, powerlines lay across the road, power and sewerage had been cut, and the community was relying on emergency water supplies located at the airport.

"We need support at this stage, because this is the first time that Milingimbi has [been hit like this]," says Margaret Lewis in Milingimbi. ( ABC News: James Oaten )

"We need support at this stage, because this is the first time that Milingimbi has [been hit like this]," resident Margaret Lewis said.

Both Galiwinku and Milingimbi could be without power, water or mobile communications for a week, authorities have said.

Further to the west, the community of Maningrida was mostly unscathed, and residents have now set about trying to contact nearby friends and family.

At 7:37am Saturday, ex-Tropical Cyclone Lam was about 20 kilometres north-west of Mataranka, moving southwest at 11 kilometres per hour.

The BoM warned thunderstorms and heavy rain which could lead to flash flooding were forecast for parts of the Daly, Gregory and western Carpentaria forecast districts.

Locations that may be affected include Wadeye, Bradshaw, Dorisvale, Katherine, Katherine Airport, Daguragu, Delamere, Timber Creek, Victoria River Downs and Litchfield National Park.