At least four people are dead after a gunman stormed a busy motel in Darwin on Tuesday evening. There are also multiple injuries and multiple crime scenes.

Witnesses told the ABC that the man walked into the Palms Motel and opened fire with a pump-action shotgun just before 6pm on Tuesday.

Northern Territory Police, Fire and Emergency Services stated in a Facebook post that they are able to confirm that a man has been taken into custody. Police do not believe the incident to be terror related.

There is no known ongoing threat to the community however a police operation remains underway.

The suspected shooter was described as a caucasian man about 45 years in age who was wearing high visibility workwear.

Chief Minister Michael Gunner, Commissioner Reece Kershaw and Deputy Commissioner Grant Nicholls have provided this update to the public and the media:

Darwin is the capital of Australia's Northern Territory and a former frontier outpost.

Prime Minister Scott Morrison has spoken out to condemn the 'terrible act of violence'.

'This is a terrible act of violence that has already, I'm advised, taken the lives of four people. There are a number of others who have - casualties but the details of that is still not yet confirmed,' Mr Morrison said from London.

He said the matter would be 'managed' and 'dealt with' by the Northern Territory government.'

'I want to thank the Chief Minister (Michael) Gunner for the way that he's working with the Commonwealth authorities but particularly I just want to extend my deep condolences and sympathies,' he said.

Mr Morrison said the community in Darwin would be 'rocked' by the attack, but advised it was 'not a terrorist act'.

Further updates will be provided as more information becomes available.