Police in Pakistan have arrested 10 people for the killings of a newlywed couple who entered into a free-will marriage in the southern port city of Karachi.

Abdul Hadi, 24, and Hasina Bibi, 19, were killed by relatives last week for marrying without permission from their elders earlier this month, according to police spokesman Qasim Hameed.

He said Mr Hadi's father and nine other relatives were arrested after the couple's bodies were found in a local graveyard on Sunday. He added that Ms Bibi's father has absconded.

He said the men had confessed to murdering the couple with knives on the orders of a "Jirga", or tribal council, for dishonouring their Pashtun culture.

Nearly 1,000 Pakistani women are killed by close relatives each year in so-called honour killings.