0:36 Jack Grealish celebrates his goal in Aston Villa's 1-0 win against Birmingham City at St Andrews Jack Grealish celebrates his goal in Aston Villa's 1-0 win against Birmingham City at St Andrews

Birmingham City say they will investigate an incident involving a steward during their 1-0 defeat to Aston Villa in the Championship on Sunday.

Jack Grealish scored the only goal of the game for Aston Villa in the 67th minute and celebrated by jumping in with the away side's fans at St Andrews.

0:33 A man invaded the pitch and attacked Aston Villa captain Jack Grealish during their match with Birmingham City. A man invaded the pitch and attacked Aston Villa captain Jack Grealish during their match with Birmingham City.

As police officers and stewards tried to come between the players and spectators, one steward appeared to clash with Grealish and his team-mate Conor Hourihane as they tried to get back on to the pitch. The steward was then led away by police officers.

In a statement, West Midlands Police said the steward was spoken to but was not arrested. Birmingham City have said they review everything that goes on at every game and they will investigate the incident.

A supporter is taken to the ground after attacking Jack Grealish

It followed an unsavoury moment earlier in the match when Grealish was attacked by a fan. The pitch invader swung an arm at the midfielder and knocked him to the floor, before being removed from the ground and later arrested.