A group of Pakistani clerics has issued a fatwa, a legal opinion pertaining to the Islamic law, against honour killing and anyone who indulges in such a practice.
Hundreds of Pakistanis, the vast majority women and girls, are murdered every year by relatives when they marry against their family's wishes. Most of the suspects in honour killings are not prosecuted.
The ruling by the Sunni Ittehad Council, which includes more than 100 prominent clerics, comes after a string of killings, including the killing of a 16-year-old girl who was burned to death by her mother for eloping with a younger man.
The council has called on the government to amend laws that allow family members to "forgive" their sons and daughters if they marry men or women of their own choice.
"It seems were are moving towards an age of barbarism," the council said in its fatwa which was issued on Sunday, a rare edict on the problem in the Muslim majority country of 190 million people.
"Burning women alive for marrying by their choice is against the teachings of Islam."
The council is affiliated with the Barelvi sect of Sunni Islam, the largest sect in Pakistan, and holds significant influence in Punjab province, where half of the Pakistanis live.
"Considering any killing in the name of honour to be justified is heresy," the council said in a press release.
Last Friday, a father in the eastern city of Lahore, the capital of Punjab, killed his daughter and her husband because he did not appprove of their marriage.
Last month, a 16-year-old girl accused of helping a young couple elope was killed and her body was set on fire.
According to the Human Rights Commission of Pakistan, more than 500 were murdered for "damaging their family's honour" in 2015.
The toll this year, as of Monday, was 233, the group said.