Claudio Ranieri says he told Arsenal manager Mikel Arteta that his side have "no respect" after his Watford team suffered a 1-0 defeat on Sunday.
Arsenal secured the three points in the Premier League clash through a second-half goal from Emile Smith Rowe.
But Ranieri felt the Gunners got the decisive goal because of unsportsmanlike conduct, as his side put the ball out of play to allow the injured Ozan Tufan to receive treatment.
Watford expected to get the ball back as play resumed, but Arsenal went on to score, much to Ranieri's disappointment.
The coach raised his objections to Arteta after the game and went on to criticise the home side in a press conference.
"We put out the ball and everybody expected Arsenal to give back the ball," Ranieri told reporters after the game.
"Sissoko and Rose said: 'give the ball to us, we put the ball out, there was an injured player'. After this it was very strange.
"There was a cross, Kiko Femenia hit the ball with the header, Sarr took the ball, in my opinion there's a big foul, but nothing happened and then they score the goal. It was very, very strange.
"Our relationship [Ranieri and Arteta] is very good, I told him there isn't respect when we put the ball out. I said there isn't respect in this action, just this."
Arteta came to his team's defence when asked about Ranieri's comments, but apologised for the offence they may have caused.
He said: "I have to defend my players, my team and my club. We are the most honest of all of them.
"Even at some stages we are naive. If he felt like that, I apologise, but there was no intention."
Arsenal are now on a four-game winning run and are unbeaten in their last 10 in all competitions.
After the international break, the Gunners will return to Premier League action with a trip to Liverpool on November 20.
Watford, meanwhile, are still 17th in the table and two points above the relegation zone. Their next match is at home to Manchester United.