More than a thousand people were told to leave a rally held in support of striking Indian famers.
People from across England drove to Birmingham and Sandwell in Saturday to attend the Kisaan Car Rally.
But those living and working in the Jewellery Quarter area of the city said the roads were blocked by traffic and people getting out of their cars for four hours.
West Midlands Police said a number of drivers were prosecuted.
The National Sikh Police Association UK advised people not to attend the rally that started in West Bromwich before travelling to Birmingham, both of which are under tier three coronavirus restrictions.
Hundreds of vehicles then made their way in convoy to the Indian embassy in the Jewellery Quarter in opposition to the reforms being introduced in India.
But once outside the consulate, many got out of their vehicles.
Resident Zahrah Ahmed said many people were not wearing masks, a truck on a roundabout stopped traffic from passing and cars were driving on the opposite side of a road.
A trader who wished to remain anonymous told BBC News the rally “blocked the whole of the Jewellery Quarter for four hours making it impossible to trade”.
West Midlands Police said there was no identified organiser and “the lack of established route” caused disruption.
The force added it told more than a thousand people to leave, three were given a £100 fixed penalty notice and people who threw flares from moving vehicles would be prosecuted retrospectively.