Fan violence at football matches appears to be on the increase once more.
Several matches in France were abandoned this season after fans rioted, while fans have been attacked on their way to matches in overseas fixtures. In Spain last week, the derby between Real Betis and Sevilla had to be called off after a fight in the stands (the rest of the match was played out the next day behind closed doors).
On Saturday, an Aston Villa player was hit by a bottle thrown by an Everton fan after their team scored at Goodison Park. And on Sunday, two arrests were made among the travelling Tottenham away support after Chelsea defender Antonio Rüdiger was hit by objects thrown from the crowd.
Less than 24 hours before that, things had reached another level altogether during an under-20 cup semi-final in Brazil.
The game saw Sao Paulo take on Palmeiras. The home side were trailing by a single goal as the match moved into stoppage time.
Two fans then invaded the pitch. One of them physically assaulted a Palmeiras player, while the other was restrained by members of the home team.
While this was going on, some objects were thrown onto the pitch, one of which turned out to be a knife.
An urgent investigation now is being conducted to find out how the knife got into the stadium in the first place. There are suspicions that it might have been contained inside a lunch box. Stewards at the gate were supposed to have searched all fans as they entered the ground. It seems that either the knife was missed, or they were lax in their duties.
The perpetrator has not yet been identified.
Fortunately, the knife did not belong to the one of the fans who invaded the pitch. The consequences could have been potentially worse in that case.
Nevertheless, there is a sense that, sooner or later, a player is going to get seriously hurt unless this trend is arrested.
Some might have thought that supporters, denied access to grounds for so long during the pandemic, would just be glad to be back inside. Instead, it seems to have unleashed some long-held primeval passions among some of them.