An 11-year-old boy who was shot at a home in northwest of Australia’s Sydney died in hospital on Thursday, police said.

The boy had been in a critical condition since being found with gunshot wounds to his face and neck at a unit in Norwest, a suburb in the Hills District of New South Wales, on Monday.

He died at Westmead Children’s Hospital at about 8pm.

Police were called to the unit on Fairway Drive at about 5pm on Monday after reports of a shooting. Paramedics treated the boy at the scene before taking him to hospital.

Five other people who were in the home at the time, including four 18-year-old men and a 44-year-old woman, described as friends or family of the boy, were not injured.

Three men were arrested. Two were taken to the Hills police station but later released pending further inquiries.

The third, Isaac Bechara, was charged with concealing a serious indictable offence. The charge applies when an adult fails to report or conceals information about a major crime.

He appeared on Tuesday at the Blacktown Local Court, where he didn’t apply for bail and was refused it.

In the days after the shooting, police said it was too early to determine what had happened, although initial reports indicated the shots were fired inside the house.

Officers were also trying to locate the firearm used, noting that no gun was registered to the address.

New South Wales police superintendent Naomi Moore said a number of people inside the home at the time were known to police and that investigators were considering their possible links to organised crime, though she said some of those present were not cooperating.

NSW premier Chris Minns described the shooting as an “incredibly distressing situation” and “a very tragic reminder of how dangerous guns are”, adding that people who fell victim to gun violence were often innocent people.

Friends and family paid tribute to the boy, who was a member of the Maronite community, a Christian denomination with a significant presence among Sydney’s Lebanese-Australians.

“Rip my baby,” his father wrote on social media. “Rest in peace little cuz,” another family member said. “Heart broken.”