Former US President Barack Obama has turned up for jury duty at a Chicago courthouse, but was dismissed by the judge without being called on to serve.

Crowds thronged the Daley Center municipal building to catch a glimpse of the 44th US president.

There was no official explanation for his dismissal, but it is not uncommon for people called to perform jury service not to be assigned a case.

Mr Obama arrived at court on Wednesday morning and left around midday.

The former president, who was once a law professor, has a house in Chicago.

Each potential juror is paid about $17.20 (£13.11) from the county.