Prosecutor Adrian Holloway interviewed the four individuals, including the drivers of two cars and two passengers, on Friday, before determining they should be detained, the Geneva justice department said on Monday.
The detainees range in age from 18 to 23.
The drivers of a BMW and Subaru were reportedly racing on the Rue de Lyon in Geneva’s Charmilles neighbourhood last Wednesday night at around 10.30pm.
During what the justice department called the “rodeo”, the vehicles struck two pedestrians who were crossing the road, one of whom, a 34-year-old man, died on the spot.
The BMW continued on and rear-ended another car, leaving the two drivers and a passenger injured, according to media reports.
The driver of the Subaru, reportedly 19 years old, fled the scene and was interviewed by police the next day at his home.
Police interviewed the other driver and a passenger in hospital last Thursday.
Based on the preliminary results of the investigation the four detainees are accused of murder, inflicting serious bodily injuries, intentional violation of basic traffic regulations and violating the responsibilities of individuals involved in a motor vehicle accident, the justice department said.
The accused deny having participated in a car race, the department said.
The justice department has obtained approval to detain the two drivers for a period of three months, while the passengers will be held for one month as the investigation continues.