Sir Alex Ferguson called on the Football Association to hit Ashley Williams with a lengthy ban after claiming the Swansea City defender "could have killed" Robin van Persie during Manchester United's 1-1 draw on Sunday.

The United manager accused Williams, the Wales team's captain, of deliberately kicking the ball at the striker's head from dangerously close range, suggesting the Dutchman's neck could easily have been broken. The incident provoked a melee, after which both players were booked, but Van Persie was able to continue without receiving treatment. He had gone to ground after being fouled by Nathan Dyer on the edge of the penalty area.

Ferguson appeared furious that tougher action was not taken by the referee, Michael Oliver, and called on the FA to take action against the defender.

"In the Van Persie situation you can clearly see that he could have been killed," he told Sky Sports News. "The FA has got to look into it regardless that he has been given a yellow card. He should be banned for a long time because that was the most dangerous thing I've seen on a football field for many years.

"It was absolutely deliberate. The whistle has gone, the game has stopped and he has done that right in front of the referee, he could have killed the lad. It was a disgraceful act."

In a BBC interview Ferguson added: "Robin van Persie is lucky to be alive … Robin could have had a broken neck."

Williams denied any malice was involved: "I tried to clear the ball and it hit him on the head. He was obviously a bit angry about that, but it was a much ado about nothing."

Michael Laudrup, the Swansea manager, was puzzled by his opposite number's sense of outrage. He said: "I don't think Alex meant 'kill him' literally. These things happen in games. You get angry in the moment, but then you shake hands and carry on."

In reality there was no handshake between the two players. At the final whistle Van Persie presented his shirt to Swansea's goalkeeper, Michel Vorm, with whom he plays for Holland, and at the same time pointed an accusing finger at Williams. He was clearly still incensed.

Ferguson was angry with Oliver's officiating throughout a match in which a Patrice Evra header was cancelled out by Michu. "The referee had one of those days where we didn't get anything out of him," he said. "It was a shocking performance. I know he is a young referee but I was disappointed with that performance."

Less contentiously, Ferguson was pleased with the way Nemanja Vidic emerged from his first full match for nearly a year after reconstructive knee surgery. "He didn't have much to do, but he came through fine."

Laudrup preferred to concentrate on an encouraging performance and result. He said: "In the same game last season we maybe had too much respect for Manchester United. Our players had only seen them on the television. This time we stood up to them and the result could have gone either way in the end."

Michu, the division's leading scorer, equalised with his 13th league goal since joining Swansea from Rayo Vallecano for only £2m last summer, and Laudrup admitted the Spaniard was playing out of position at centre-forward. The manager said: "Today he scored a typical centre-forward's goal, he was there in the right place for the second ball. But he is really a midfield player who can play up front. In Spain, 90% of his goals came from the second line. He can play either No9 or No10, but he is really a second striker or an offensive midfielder."

Laudrup intends to sign an orthodox centre forward in January and is known to be looking for another Spanish bargain.