John Stones branded Manchester City's performance in the final 30 minutes as "unacceptable" as they were thrashed 5-1 by Arsenal on Sunday.

After briefly levelling the game at 1-1, City conceded four second-half goals at the Emirates, including three in the final half hour.

Stones apologised for the display before criticising the late collapse.

"It's difficult, I think all of us don't take losing well," Stones told Sky Sports.

"Hard for me to put into words. Sorry to the fans that traveled to the game and watched that, how we played in the last 30 minutes was not acceptable.

"Not nice to be involved in that when it's not your team or yourself within those situations."

Asked later about the comments, Pep Guardiola said agreed with the England defender's assessment.

"You can lose by two or three or four, but in the last 30 minutes we have to do it and we don't have a defence," said Guardiola.

"We had a plan and we didn't do it because they have pride and want to solve it but that's not the way.

"At that level, you have to stick to what we did. Unfortunately what happened, happened and hopefully we can learn the lesson for the future."

Guardiola has watched his team give up two-goal leads against Brentford and Paris Saint-Germain in the last month.

The defeat at Arsenal was another example of City letting a situation quickly unravel. And after a difficult season which has not been up to their usual standards, Guardiola admitted his players are "fragile."

"You can have setbacks but this season it doesn't matter what happens," said Guardiola.

"We can lose but we have to continue to do what we do. That is how you are stable. We cannot think we are going to solve it in another way. We are not used to that.

"They can be fragile but they have a duty to do what they have to do and they didn't do it. We can learn and always there is a margin to get better."