The youths, all male and aged between 14 and 20, had gone cycling and gathered on Lorong Halus Bridge on April 16 at around 2am, said the police on Wednesday (April 22).
The youths had taken a video showing one of them on the bridge commenting on the circuit breaker measures and making offensive gestures.
The video was shared among themselves and was later circulated on social media.
Having received several reports of the video, officers from the Ang Mo Kio Police Division established the identities of the subject and five others with him within nine hours.
They were issued fines for flouting various safe distancing measures under the Covid-19 (Temporary Measures) (Control Order) Regulations 2020.
The police urged the public to take the circuit breaker measures seriously.