A 26-year-old college teacher damaged her left eye and her three sisters, also teachers, suffered burns after two men on a motorcycle threw acid on them in UP's Kandhla town, 80km from Meerut.
Kamarjahan, 30, Isha, 26, Ayesha, 24, and Sonam, 20, were returning home after invigilating a board exam at a local high school at around 5.30pm Tuesday when they were attacked.
"The victims were walking together when two men on a bike made lewd remarks and the man riding pillion splashed acid on all of them," Abdul Hameed, the senior police officer investigating the case, said.
On hearing the sisters' cries, people from nearby shops gave a chase to the assailants but they managed to flee.
The women were rushed to a local hospital. Isha, who suffered serious injuries, was referred to Sir Gangaram Hospital in Delhi.
The other three were discharged from a Muzaffarnagar hospital on Wednesday afternoon. A 10-year-old girl, who was walking with them, escaped with minor burns.
Isha's left eye has been completely damaged and the right, too, has suffered injuries, doctors at Gangaram said. She was stable but had burns on her chest, neck and face.
"It is too early to say about the recovery as her wounds are fresh. Right now we are concerned about saving her vision and containing infection," said Dr Mahesh Mangal, chairman, department of plastic and cosmetic surgery at Gangaram.
The police are yet to identify the assailants.
"We are examining the SMS and call details of the victims to ascertain the identity of the attackers and the reason for the attack", said Saharanpur DIG Durga Charan Misra.
The incident came to light on the day President Pranab Mukherjee signed the new anti-rape law, which also defines an acid attack as a crime, punishable by life imprisonment.
With agency inputs