Police have said there is no clear motive for the fatal stabbing of 21-year-old Luke Manassa and are looking at the possibility of a mistaken identity case, as two teenagers are charged over what officers believe may have been a contract killing.

Manassa was allegedly attacked by two men in the driveway of a home on Driftway Drive in Pemulwuy, at 10.45pm on June 26.

He had just arrived at the home with his girlfriend, NSW Police said. 

The 21-year-old suffered stab wounds in the attack. He then got into his car and drove a short distance before succumbing to his injuries.

Paramedics treated the man, however, he could not be revived.

Detective Superintendent Joseph Doueihi said the investigation had not found a clear motive as to why Manassa was targeted.

“Investigations today have not identified a clear motive as to why someone would want to murder Luke, he is not known to the NSW Police force.”

“It perhaps (was) the wrong target… more than likely this is a case of mistaken identity, but it’s still early days before we can absolutely confirm that.”

He also said that he believes two teenagers were contracted to kill someone, although police do not know who hired them or why.

Doueihi called the attack “very amateurish” and said it did not have the hallmarks of the usual gang hits, which usually have high levels of planning.

Manassa did not live at the home but he was known to visit the property.

Police are looking into the possibility that the occupant of the home was the intended target.

Detectives executed multiple search warrants yesterday morning at homes in South Penrith, Mt Druitt and Woodcroft.

Doueihi said two youth offenders, alleged to be part of a Sydney street gang, were arrested and charged over the attack.

A 17-year-old man of African background was arrested from the home in South Penrith.

He was on bail at the time of the offence and breached curfew to allegedly commit the crime, Doueihi said.

He also said the teen had been charged for other offences but was continuously let out on bail.

He was taken to Penrith Police Station where he was charged with murder.

A 16-year-old man of Middle Eastern background was arrested from a home in Mount Druitt.

He was taken to Mt Druitt Police Station, where he was also charged with murder.

Both men were refused bail and will front Children’s Court today.

Police allege they found a getaway car at one address in Woodcroft. 

Detectives believe there are several other people involved.