A man has been arrested after a fatal shooting in a Western Sydney apartment that police believe has “strong links” to organised crime.

Abdullah Bahsa, 38, and another man were allegedly assaulted by a group of five “heavyset” men dressed in black at an apartment on Shale Street in Lidcombe about 4am on Monday.

WATCH THE VIDEO ABOVE: Man dies after shooting in Lidcombe

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Bahsa was shot in the lower abdomen and rushed to Westmead Hospital along with the other victim, where Bahsa later died.

The second man suffered non-life-threatening injuries.

Following investigations, police arrested a man in Ryde about 12pm.

Two men were rushed to hospital, with one dying after being shot multiple times. Credit: 7NEWS

He was taken to Gladesville Police Station where he is assisting officers with inquiries.

Police said the group entered the apartment block about 11pm on Sunday before Bahsa arrived home soon after.

The gunshot, which rang out about five hours later, shocked residents.

“I literally live in the same building, so it’s definitely pretty scary,” one resident told 7NEWS.

“It was just one bang — a very loud one,” another said.

Superintendent Robert Toynton said the attack was targeted and that police were looking at links to organised crime.

“From what we’ve discovered so far there are strong links to organised crime in relation to this homicide and the police will be following through those lines of inquiry with the assistance of the state crime command’s homicide squad,” he said.

Bahsa died after being rushed to the hospital. Credit: 7NEWS

“We need to find out what these people were doing before this interaction they’ve had in the apartment, I can confirm the crime scene is within the apartment of the Shale St address.”

7NEWS understands Bahsa had connections to Sydney’s underworld.

The two victims were known to each other, Toynton said.

The man that remains in hospital is receiving treatment and assisting police.

Police are now investigating what the men were doing inside the unit, reviewing CCTV and speaking with neighbours.

Police outside the apartment block on Monday morning. Credit: 7NEWS

Toynton called on members of the public in the Lidcombe area to contact police if they heard or saw anything suspicious from 11pm on Sunday night to 4am on Monday morning.

“Someone must have seen something, someone must have heard something, someone must have seen a car or these offenders leaving on foot,” he said.

“We’ve got a lot of resources looking at the job, we’ve got our best investigators looking at this job and we wont rest until someone’s held accountable.”

Anyone with information should contact Crime Stoppers.