Update 10pm: The man, aged in his 20s, shot in Finglas this afternoon as passed away. Gardaí are now investigating his murder.

The shooting happened on McKee Road in Finglas, in the north of the city, shortly before 3:15pm.

The victim, understood to be 25 years old, was sitting alone in a white VW Golf car when a silver/grey five-door VW Golf, which had alloy wheels, approached him.

A number of shots were fired before the silver/grey VW Golf left the scene at speed towards Clune Rd and Jamestown Road, Finglas.

The scene has been sealed off for technical examination by the Garda Technical Bureau.

A car has been found burnt out in the Victoria Bridge area on the Naas to Rathangan Rd which may be involved. It has also been preserved for a technical examination.

This evening, Superintendent John Quirke at Finglas Garda station has appealed for any witnesses in the McKee Road or Victoria Bridge area, as well as anyone who saw a silver/Grey VW Golf in the Finglas area before or after the shooting to contact gardaí in Finglas on 01 6667500, the Garda Confidential Line on 1800 666 111 or any Garda station.

The victim is described by security sources as having been close to Alan Ryan, the Real IRA boss gunned down near his family home in the Grange Lodge estate in Clongriffin in 2012.

"He has been brought to the Mater Hospital. His condition is described as serious," a Garda spokesman said.

One Garda source said it was "unlikely" the attack was directly linked to the bloody gangland feud which saw gunmen storming the city's Regency Hotel earlier this month, killing one and wounding two others.

That shooting, and a suspected follow-up reprisal in the north inner city, led to heavily armed gardaí being put on patrol in parts of the city.