Arrest after man shot dead in 'targeted attack'

Police believe the shooting was carried out by offenders with organised crime links.

Officers arrested a man from Ryde in northwest Sydney about midday and took him to a police station for questioning.

"This is a targeted attack. This is not a random attack," Superintendent Robert Toynton told reporters on Monday.

He described the accused shooters as heavy-set men dressed in black clothes and urged the public to come forward with any relevant information.

"NSW Police take gun-related crime very seriously ... we're throwing all the resources we can at this incident and hopefully we can make a quick arrest," Supt Toynton said.

A second man found at the scene with non-life-threatening injuries was taken to hospital. 

A crime scene has been established and investigations are ongoing.