Football fans involved in "unacceptable behaviour" should be put in jail for "six months, minimum", says Dundee manager Jim McIntyre.
There have been a number of incidents in recent months, including a Hibernian fan confronting Rangers captain James Tavernier during a Premiership match at Easter Road.
Aston Villa's Jack Grealish was also attacked on Sunday.
"It's a disgrace what's happened in the last couple of weeks," he said.
"From coin throwing over the last couple of months to people actually entering the field of play. It's just unacceptable behaviour.
"The only way to deal with it is to make sure they get six months in the jail, minimum sentence - then you'll soon see it stop."
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'We're aiming to cause an upset against Celtic'
On the back of a narrow 1-0 defeat to Hearts, 11th-placed Dundee face league leaders Celtic on Sunday at Dens Park.
McIntyre says that his side are capable of causing an upset, despite a run of three losses.
"Apart from the Rangers result, there's been a lot of positives in both our performances," he said.
"We know it's going to be difficult, but everybody's been involved in upsets before, and that's what we'll try and cause."