Police are trying to identify 15 people who took part in a pro-Palestinian convoy that caused "danger to other road users".
A total of 80 cars "stopped twice on major roads" - the A13 and the Limehouse Link Tunnel - Scotland Yard said.
It caused "not only disruption but danger to other road users".
Officers became concerned because on previous occasions, "convoys of cars have passed through Jewish communities with occupants waving flags and shouting anti-Semitic abuse", T/Commander Karen Findlay said.
"They understandably caused significant concern, fear and upset."
Police believe the group planned to drive to the Israeli Embassy off Kensington High Street, Ms Findlay added.
The police helicopter was deployed and the cars were held in Exhibition Road, South Kensington, before a dispersal order was put in place.
"All 80 cars were given notices under Section 59 of the Police Reform Act ordering them to disperse and cease their participation in the convoy or face being seized," a spokesperson said.
"One vehicle was ultimately seized, with fixed penalty notices for various road traffic offences issued to 18 drivers.
"A further nine vehicles were served with prohibition notices after defects were found making them unfit for use."
The cars are believed to have set off from a car park in Hancock Road, Tower Hamlets.
Images have been released of individuals "believed to have been involved in offences as part of the convoy".
"The public have been a great help in recent weeks when similar appeals have been made and I have no doubt they'll continue to do the same," Ms Findlay said.