Police in the Indian state of Uttar Pradesh have filed preliminary charges against two women accused of killing their daughters.
The women, who were neighbours and are both Muslim, were reportedly furious with their daughters for eloping with Hindu men, police told the BBC.
Zahida, 19, and Husna, 26, were strangled last week after they returned home to make peace with their families.
The two mothers are yet to make an official response to the accusations.
One of the accused is quoted by the Indian Express newspaper as saying after being arrested, "How could they elope with Hindus? They deserved to die. We have no remorse."
Police say they are still trying to ascertain if the women assisted each other.
Zahida and Husna fell in love with two Hindu construction workers and eloped and got married before returning home to the town of Baghpat last week. Their mothers were arrested by police on Friday.
Correspondents say that marriages between Hindus and Muslims are not common in India. In rural areas especially they are frowned upon by both communities.
Last week India's Supreme Court ruled that people convicted of so-called honour killings should face the death penalty.
"It is time to stamp out these barbaric, feudal practices which are a slur on our nation," the court said.
According to one recent study, hundreds of people are killed each year in India for falling in love or marrying against their families' wishes.
Convictions for so-called honour killings usually carry life sentences.