Three women were attacked by blades within a span of half an hour in the Mongolpuri area on Saturday.
The incident comes a week after the Delhi Police arrested two men, including a "spurned lover", for attacking five women on their faces with a surgical blade.
Saturday's incident took place when two men on a red Hero Honda Hunk motorcycle attacked the women on their faces, possibly with a filer attached to a nail cutter.
The police said the women were returning home when they were attacked. This takes the total number of women who were attacked in such manner in the past one month to eight.
"One of the victims told us that there were two men on the motorcycle and it was red in color. From their description it seems that a nail filer has been used. One of them sustained a cut on her face across her right cheek," said Chaya Sharma, deputy commissioner of police (outer).
The police said all three incidents were reported from different parts of Mongolpuri area within a span of half an hour. The last incident was reported around 8.30 pm.
The police ruled out the involvement of any gang in the crime and said that the accused might have been copycat criminals.
The women have been rushed to Sanjay Gandhi Hospital, where they were given medical aid.
"We have registered a case and are investigating. One of the two men who attacked the women used his left hand to slash their faces," said the police officer.
After the incident was reported, people came out on the streets and protested against the incident.
For the earlier crimes, the police had arrested the two accused - Vishal Khullar (22) and Rohit Kumar (26), both petty criminals.