'Welcome back, football': Manchester United and Leeds fans clash on the streets ahead of Saturday's Premier League opener (VIDEO)

Fans of Manchester United and Leeds United, two historic rivals in English football, have clashed on the streets of Manchester city center in the hours before Saturday's early kick-off at Old Trafford.

It has been a decade and a half since the two age-old foes have played each other in the English top flight in fans, after Leeds' promotion to the Premier League was played almost entirely in the absence of supporters last season - and the two sets of fans don't seem to be willing to cede an inch to one another as Saturday's kick-off inches closer.

Several separate videos posted to social media early Saturday have showed fans of both teams engaging in testy exchanges and taunts with, with at least one video showing a pack of retreating fans being attacked by another set of supporters. 

The video concludes with one supporter falling to the ground where he is set upon by several other fans who punch and kick the prone man, while another football fan appears to strike him repeatedly with a trash can. 

Sirens can be heard in the background before a sole police officer arrives on the scene, prompting the angry mob go scatter.

It was also reported online that some Leeds fan where chanting in reference to the Munich air disaster of 1958, the darkest episode in Manchester United's history in which several Manchester United players died in a plane crash while returning home from a European Cup game in Belgrade.

It is thought that at least one violent incident occurred at the Spinningfields area of Manchester city center, a part of the city known for being a popular destination for entertainment and shopping.

"Just gone 10am and it’s already kicking off with Leeds and Man Utd fans," wrote on person online who captured the footage.

"So the Leeds fans are enthusiastic about the first game of the season," said another wryly. "Going to be an interesting game today."

"Leeds fans chanting Munich across the city centre whilst trying to fight evolution," wrote another sarcastically. "Welcome Back Football."