Police described a group of football fans as "idiots" after a number of people were arrested at a derby match between Newcastle United and Sunderland.
Nine arrests were made during the day for offences of assault, disorder and drunkenness, including one person arrested for going on to the pitch at St James' Park.
A further group were arrested after the game when a large number of Newcastle United fans gathered outside the city's Central Station with the intention of attacking Sunderland fans and officers, Northumbria Police said.
There was a large police presence in the city and in and around the stadium in an attempt to stop a repeat of trouble seen at previous matches between the two teams.
A Northumbria Police spokeswoman said: "Disappointingly, nine arrests were made over the course of the day for offences of assault, disorder and drunkenness, including one for going on the playing area.
"There were additional arrests made outside the Central Station area after a very large group of Newcastle fans gathered intent on causing trouble post-match."
Chief Superintendent Neil Mackay said: "The overwhelming majority of fans were well-behaved and wanted nothing more than to attend the match free from the fear of violence, disorder or other crime.
"Despite this and our warnings about the penalties that awaited trouble-makers, there were still some willing to risk their freedom by trying to spoil the day for others."
Mr Mackay continued: "I wish to apologise for the inconvenience caused to decent members of the public when dealing with the idiots gathered outside Central Station intent on attacking Sunderland fans and police officers."
A sell-out crowd of 52,084 watched as the match finished in a one-one draw.
