With the world's eyes on Buenos Aires, Saturday's Superclásico Copa Libertadores final second leg between arch rivals River Plate and Boca Juniors has been postponed for 24 hours, after an attack on the Boca Juniors team bus that left players affected by smoke inhalation from tear gas and injuries from shattered glass from broken windows.

Alejandro Domínguez, the president of the CONMEBOL football association – the South American football governing body – told Fox television that the two teams had agreed they couldn't play under such conditions, and the game will now take place at River's Monumental stadium at 5pm local time.

The two sides are locked at 2-2 from the first leg two weeks ago, which was also delayed 24 hours but due to the weather.

The decision came after anger from Boca Juniors players, who said that the competition's organisers were forcing them to play in Saturday's final second leg, despite having been attacked with "pepper spray, sticks and stones" from River Plate's fans on their way to the ground.

The Superclásico was delayed more than two-and-half-hours before the match was cancelled. Despite reluctance from Boca players and staff, CONMEBOL had said the match would be played at 7.15pm, as a capacity crowd awaited news inside the stadium.

"We're not in a condition to play," complained Boca's veteran forward Carlos Tevez, when the match was still due to go ahead.

"They're obliging us to play," added the 34-year-old, a Copa Libertadores winner with Boca in his first of three spells at the club in 2003.

CONMEBOL had earlier delayed the match from 5pm to 6pm due to the bus attack. Local television stations had reported Boca were pushing for the game to be called off.

Boca players were left coughing and teary eyed after the attack that shattered several of their bus's windows. Three reportedly went to hospital.

'We can't play'

"They attacked us from everywhere," said Boca midfielder Pablo Perez, who was taken to a local hospital for treatment before returning to the ground.

"Pablo has just returned from hospital and has a bandage on his eye," added Tevez.

"Other team-mates have cuts. We've only just been able to breathe well because we were affected by the gas. We can't play like this," said Tevez.

In shameful scenes, a bizarre statement from CONMEBOL's medical commission shown on television said some players had suffered "superficial cuts" and that there was no medical reason to postpone the match.

The attack came despite the bus travelling with heavy police protection ahead of clash between the two most popular teams in the country – dubbed the biggest club match in Argentine football history.

"They threw pepper spray, sticks and stones. It came in the bus from everywhere," said central defender Carlos Izquierdoz.

Television pictures showed Boca players being attended to by medical staff in their dressing room at the stadium.

'Overwhelmed by vandalism'

A Boca official told the press that the pepper spray came from the police trying to disperse River fans, though others suggested it had been thrown at the bus.

"There was a lack of control in the last streets close to the Monumental. The police were overwhelmed by all the vandalism and had to disperse the River fans with tear gas," said the unnamed official. "Because of the wind and the broken windows, it entered the bus."

There will be no Boca fans at the second leg tomorrows, as expected today. Travelling supporters have been banned at all local football matches since 2013 due to hooliganism, with a few exceptions.

Football-related violence has cost the lives of more than 300 fans in Argentina over the last 50 years, according to figures from the Salvemos al Futbol (Let's save football) charity.

- TIMES/AFP