Campaigners say there are up to 150 acid attacks every year
Several men have been arrested in connection with an acid attack on three girls in Pakistan's Balochistan province last week, police say.
The sisters, aged between 14 and 20 years old, were attacked as they walked from Kalat city to Pandarani village.
The girls suffered serious burns on their faces and bodies when two men on a motorcycle drew up and threw acid over them.
Campaigners say there may be 150 acid attack victims in Pakistan each year.
The police named the girls as Fatima Bibi, 20, Saima Bibi, 16 and Sakina Bibi, 14.
The girls had been on their way to a wedding celebration outside the town of Kalat when the incident happened.
In recent days there have been several demonstrations condemning the perpetrators with protesters saying such attacks are against Baloch traditions.
Two weeks ago, an unknown group - the Baloch Ghairatmand Group (the Honourable Baloch Group) - claimed responsibility for a similar attack on two women in a market in Dalbandin city.
The group had warned women to wear the hijab, the traditional Muslim headscarf, and not to visit markets unaccompanied by men from their families.
The attack was criticised by Balochistan's political leaders as well as armed rebel groups, who said it had been carried out by elements that wanted to push the Baloch people back in time.