LONDON - The number of people arrested at a Saturday protest in support of advocacy network Palestine Action has been confirmed as 532, London's Metropolitan Police said in an update on Sunday.

As of 1 pm local time (1200 GMT) on Sunday, 18 people remained in custody. Police said those whose details could be confirmed had been released on bail.

Around 500 to 600 people participated in the protest, which began at Parliament Square, and at least 365 were arrested during the event, London's Metropolitan Police said on Saturday.

Pictures on social media showed protestors holding signs reading "I oppose genocide." A video released by The Guardian features an arrested woman speaking to the camera, saying, "Arrest the people who are selling arms, killing and bombing ..."

In July, Members of Parliament voted to proscribe Palestine Action as a terrorist group after its members broke into Royal Air Force Brize Norton in June.