A local resident passing near the train station of Cagnes-sur-Mer, southern France, thought he had seen a foot and raised the alarm.
The death of 21-year-old Salomé has been recorded as the 100th case of femicide this year.
It comes as the government announces measures to combat the killing of women related to domestic violence.
According to several neighbours, the young woman was killed by her partner during a violent attack which took place in the street at night after a row, French media report.
"She was telling him everything she thought and he did not like it," one eyewitness told local media. "He hit her, hit her against the wall, stomped on her stomach, on her head."
An investigation has been opened by the local prosecutor's office for femicide, and the women's companion has been arrested.
In 2018, the ministry of the interior had recorded 121 femicides. On Sunday, the 101st case was recorded, that of a 92-year-old woman killed by her 94-year-old husband in southern France.
In Europe, France is said to be among the countries with the highest rate of women killed by their partner, with 0.18 victims per 100,000 women, according to 2017 Eurostat figures.
This compares with a rate of 0.13 in Switzerland, 0.11 in Italy and 0.12 in Spain, but is less than in Germany (0.23).
In June, Spain recorded the 1,000th murder of a woman by a partner since records began in 2003.
The country has developed a system of special courts reserved exclusively for cases of sexual violence against women.