Eight men have been arrested over one of Sydney's gangland executions, more than a year after Mehmet Yilmaz was gunned down in the street.

The 29-year-old was shot at point-blank range in front of his fiancee while getting into his car in St Marys on September 9.

Police said Yilmaz was not formally aligned with any gangs but was believed to be closely linked with one.

Eight men have been arrested over one of Sydney's gangland executions, more than a year after Mehmet Yilmaz was gunned down in the street (pictured)

The 29-year-old was shot at point-blank range in front of his fiancee while getting into his car in St Marys on September 9

Police said Yilmaz was not formally aligned with any gangs but was believed to be closely linked with one

Two men have been arrested over kidnapping and assualt by Strike Force Osprey, a team dedicated to investigating the eight gangland killings

Homicide squad detectives say he was kidnapped and assaulted in the weeks before his murder in western Sydney.

Two men have been arrested by Strike Force Osprey - a team dedicated to investigating the eight gangland killings - over the kidnapping and another six were in custody over the murder, police said on Thursday.

A 40-year-old man was charged over the alleged kidnapping and assault and was refused bail, according to NSW Police.

The 40-year-old man was arrested September 21 and will face court Thursday.

Since Tuesday, five men have been arrested including a 28-year-old man who was charged with murder, direct criminal group and participation in a criminal group.

The 28-year-old man was refused bail and will appear in court Thursday.

A 25-year-old man and 31-year-old man were charged with murder and participation in a criminal group and were refused bail.

The 25-year-old man will face court Thursday and the 31-year-old man is expected to face court Friday.

Six men are in custody over the murder, Homicide Squad Commander Detective Acting Superintendent Jason Dickinson (pictured) said Thursday

A 40-year-old man was charged over the alleged kidnapping and assault and was refused bail, according to NSW Police

A 25-year-old man and 28-year-old man were charged with accessory after the fact to murder and participation in a criminal group and were refused bail.

The 25-year-old is expected to face court November 3 and the 28-year-old will appear in court December 1.

Strike Force investigations executed six search warrants at Blackett, Meadowbank, Mt Druitt, Stanhope Gardens, St Marys and The Ponds Thursday morning.

Two men, aged 28 and 46, were arrested during the operation.

Since Tuesday, five men have been arrested including a 28-year-old man who was charged with murder

Mr Dickinson said this week's operation (pictured) was successful after more than 12 months of investigation

Strike Force investigations executed six search warrants at Blackett, Meadowbank, Mt Druitt, Stanhope Gardens, St Marys and The Ponds Thursday morning (pictured)

The 28-year-old man was charged with accessory after the fact to murder and participate in a criminal group and was refused bail before he is expected to face court Thursday.

The 46-year-old man was charged with take/detain in company with intent to get advantage and occasion bodily hair and wound with intent. He was refused bail and will face court Thursday.

Homicide Squad Commander Detective Acting Superintendent Jason Dickinson said this week's operation was successful after more than 12 months of investigation.

'Earlier in the investigation, Strike Force Raptor seized 84 firearms and more than 12,000 rounds of ammunition and the Drug Squad seized more than $400,000 worth of illicit drugs,' Mr Dickinson said Thursday morning.

A 25-year-old man and 31-year-old man were charged with murder and participation in a criminal group

A 25-year-old man and 28-year-old man were charged with accessory after the fact to murder and participation in a criminal group

All the men were refused bail and will front court in coming weeks with more arrests expected to be made as investigations continue

Investigations are continuing and more arrests are expected.

Yilmaz's death is one of 10 underworld shootings and apparent revenge executions across Sydney since 2015.

The deaths included Mafioso kingpin Pasquale Barbaro, 35, who was executed outside an Earlwood home in November 2016.

Barbaro's grandfather and cousin were both killed in gangland hits and there were unconfirmed rumours he was an informant.

Gangland figure and convicted killer Ahmad, 40, was killed on a rooftop car park of Bankstown Central shopping centre in April 2016.

His execution was believed to be in retaliation for the fatal shooting of Safwan Charbaji outside a Condell Park panel beater several weeks earlier.

A key suspect in the Ahmad murder, Hamad Assad, was killed at St Georges Hall home last October.

A month ago, the shopping centre rooftop where Ahmade was killed was 3D laser-scanned to help detectives progress their investigation.