Strathclyde Police have criticised those responsible for trouble at an Orange march in Glasgow's east end.
The traditional Orange marches take place in July
Chief Superintendent Kenny Scott said despite co-operation from parade organisers, there were "disgraceful scenes" during Tuesday's parade.
There were 20 arrests, seven for breaches of the peace and 13 for sectarian breaches of the peace.
The Orange Order voiced disappointment but stressed that those arrested were not involved in the parade.
Police said that the 19 men and one woman would be subject to a report to the procurator fiscal.
Mr Scott said: "I am extremely disappointed with the level of disorder and drunkenness shown last night.
"Despite good co-operation from the organisers of the parade, yet again we witnessed disgraceful scenes involving sectarian language and singing from a sizeable number of people following the parade.
"This necessitated a high level of police intervention which resulted in an unacceptable number of arrests for a parade of this size."
Robert McLean, executive officer of the Grand Orange Lodge of Scotland, said: "Strathclyde Police has since confirmed that they had very good relations with the organisers in the lead up to the event and that none of those arrested were members of the lodge, or band personnel, or in any way involved with the parade.
"We can be proud that our efforts to continue the excellent behaviour from those officially connected with the Orange Order have been maintained and can only express our sincere disappointment that a small number of the 1,500 people who watched the parade have caused the police concern."
In May, police in Glasgow pledged to crack down on unruly elements during the marching season.
Officers said they would use their new powers to prosecute anyone committing sectarian offences.
This followed a parades review, carried out by former Strathclyde Police chief constable Sir John Orr, which recommended that every march should be assessed so that the community could be consulted.
He suggested marches be blocked if there was a risk of intimidation to the local community or of serious disruption.
Under the measures, groups must give 28 days notice of a march, instead of the present seven.