Frenzy outside scene of fatal stabbing attack

A knifeman is on the run in Sydney after a fatal stabbing attack at Marrickville in the city's inner west.

Emergency services were called to Marrickville Road at about 7.40pm last night after reports that a man aged in his 30s had been attacked.

Paramedics performed CPR but the victim died at the scene outside a Guzman y Gomez fast food restaurant.

The attack sparked a frenzy of activity around the victim's body, with the surrounding streets placed into lockdown for several hours to preserve the crime scene.

Several people, understood to be family members of the victim, tried to see his body but were pushed back by police.

At one point, an officer was forced to pull out a Taser in an attempt to keep them away from the scene.

Witnesses told 9News that emergency responders tried to desperately to keep the man alive.

"We just saw one guy on the floor and the police was helping him," a woman said.

"And then after we came back from Woolies the guy had passed away.

"It makes me so sad because I'm from overseas and I know that this country is so safe. And to be honest, I didn't expect this kind of thing to happen."

The knifeman is still on the run and police are appealing for help to track him down.

NSW Police said there was no clear motive for the attack and no information on the potential suspect has been released.