Thousands of Swansea City fans have seen their team fail to reach the Championship in a dramatic penalty shoot-out at the Millennium Stadium. Around 34,000 fans travelled to see the club play Barnsley in the League One play-off-final.
One coach had its windows smashed after it was hit with stones near Sophia Gardens in the city, South Wales Police said.
Transport police made 15 arrests after the match but praised fans' behaviour.
It is understood the coach was carrying Swansea fans but had not been parked in one of the designated areas.
British Transport Police's area commander Chief Supt Peter McHugh said: "Generally the atmosphere was peaceful.
"Sadly however, there remains a small minority who consider engaging in disorder and ruining it for others. The vast majority of fans were well behaved."
Most of the arrests were for public order offences.
After drawing 2-2 at the end of extra time, the club missed out on what would have been their return to English football's second tier after 22 years.
The club said demand for tickets for the game in Cardiff has been unprecedented with many fans queuing for hours at the Liberty Stadium when tickets went on sale to secure their place at the final.
 Police said there were no arrests before the match |
Earlier this week the Swans were given extra tickets by the Football League to meet demand.
Michelle Hills, manager of the Liberty Stadium shop, said demand for Swansea City merchandise had been huge in the build-up to the match.
She said: "Sales this week have been absolutely fantastic, the atmosphere around the club is brilliant at the moment.
"We've had a t-shirt made especially for the final and it's selling out.
"As soon as it's on the shelf, it's gone."
It was the second game for Swansea at the Millennium Stadium in the space of two months, following their 2-1 victory over Carlisle in the Football League Trophy final in April.