"The 25-year-old woman was rushed to Deen Dayal Upadhyay (DDU) Hospital where her condition is serious.
The reason behind her suicide attempt is yet to be ascertained," a police official said.
According to the police, the incident took place at around 1 PM at Janakpuri East Metro station when the train was heading towards Noida City Centre Metro station from Dwarka.
"As the incident took place in non-peak hours, trains were running at ten-minute frequency following which metro services didn't suffer to a great extent.
The woman was shifted to the hospital soon after the incident," a metro official.