A team of detectives set up to find the extremists today released images taken from CCTV and by police cameramen in an attempt to identify troublemakers. On 3 January, 12,000 people marched from Embankment to Trafalgar Square. Later about 2,000 people marched on to the Israeli embassy where a group tried to break through the police lines, attacking officers. Afterwards a knife was found embedded in the embassy gatepost which police believe had been thrown at them. Thirteen people were arrested but police are seeking 17 others. On 10 January police outside the embassy came under attack after a march involving up to 20,000 people.