Police arrested Ilyas and Qasim, who suspected Nasreen of having an affair with the man currently under treatment at Abbasi Shaheed Hospital.
Hundreds of women are murdered by their relatives in Pakistan each year on the pretext of defending what is seen as ‘family honour’.
In June, sixteen-year-old Zeenat Bibi was killed in Lahore by her mother for marrying a man of her own choice in a case that sparked condemnation throughout the country.
It was swiftly followed by another killing, of a couple in Lahore who married without their family´s consent.
Earlier, in April, police arrested a young man in Orangi Town for slitting his teenage sister’s throat and watching her bleed to death. Hayat Khan, aged around 20, used a kitchen knife to murder his 16-year-old sister Sumaira after he found her talking to a man on her mobile phone at their home.
A film on honour killings in Pakistan won an Oscar for best documentary short in February.
Prime Minister Nawaz Sharif vowed to eradicate the “evil” amid publicity for the film, “A Girl in the River: The Price of Forgiveness”.
Also earlier in June, the Sunni Ittehad Council had issued a fatwa, or religious ruling, declaring “honour killing” over perceived damage to a family’s reputation against the teaching of Islam, and anyone who carries out such an attack a heretic.