The mainly Kurdish region of Diyarbakir, in southeast Turkey, was rocked by a massive explosion on Thursday night said to have been caused by Kurdistan Workers' Party (PKK) militants loading explosives onto a truck.
Four people, all PKK militants, were initially said by the authorities to have been killed in the blast, which the interior ministry blamed on explosives detonating prematurely.
But the local governor's office later confirmed media reports that a dozen citizens were still missing after the immense blast, which reportedly involved some 15 tonnes of explosives.
A statement by Diyarbakir prosecutors late Monday said DNA testing based on body parts sent to Istanbul experts had confirmed 13 more people had been killed in the blast.
Their remains will now be passed onto families for burial later in the week.
The statement means that the confirmed death toll from the incident is now far higher than had been previously admitted by the authorities.
It said that 23 people had been wounded in the blast and three more had been confirmed dead in the immediate aftermath of the explosion, putting the total death toll at 16.
It was not clear if these three fatalities referred to the PKK militants mentioned previously by the authorities or other civilians.
Signup to our newsletter and follow us on Facebook and Twitter!
Reports had said earlier that authorities had conducted three investigations of the scene, collecting body parts from a half kilometre area which were sent to Istanbul for analysis and DNA identification.
An AFP correspondent who visited the scene on Friday saw body parts still strewn around the area and was told by villagers that up to 16 people were missing.
The blast left a gigantic crater in the ground which locals inspected in a state of shock.
In a statement, the PKK also said the explosion was accidental, claiming the vehicle exploded when anti-PKK villagers opened fire on the truck.
The group said the explosives were meant to be transferred to another location and not detonated. It offered condolences to the families of the bystanders who died but said it was not to blame for the loss of life.
Turkey has been waging an offensive against the PKK after the collapse in 2015 of a two-year ceasefire declared by the group.
Hundreds of members of the Turkish security forces have been killed in attacks since then although civilian deaths in the conflict have rarely been confirmed.
Over 40,000 people have been killed since the PKK took up arms in 1984 demanding a homeland for Turkey's biggest minority. Since then, the group has pared back its demands to focus on cultural rights and a measure of autonomy.