A UKRAINIAN teenager has died three weeks after being set on fire in a gang rape attack by youths that shocked the nation and raised doubts about the competence of police.

Oksana Makar, 18, was raped by three men in their early 20s, strangled with a cord, burned and left for dead in an attack in the southern Ukrainian city of Mykolayiv, investigators said.

She was found by a passer-by after she was dumped by her attackers at an abandoned construction site. She was taken to hospital in a critical condition with burns over 55 per cent of her body, requiring the amputation of one of her arms.

She died overnight of her injuries in a specialist hospital in the eastern city of Donetsk where she had been taken after her rescue, the clinic said.

Her heart stopped beating after she suffered a pulmonary haemorrhage and she died despite three attempts to resuscitate her, the chief doctor of the Donetsk Burns centre, Emil Fistal, said.

He said the fact she was able to survive for three weeks since the attack, which occurred on March 9 or 10 according to various sources, had only been possible due to intense treatment and therapy.

"Imagine. She was strangled and they (the attackers) thought she had died. So they burned her. She was lying there 10 hours in the freezing cold and inhaled the by-products of the burning," Dr Fistal said.

President Viktor Yanukovych sent condolences to her relatives while Prime Minister Mykola Azarov vowed that the attackers would be punished "without compromise".

"Millions of Ukrainians believed that Oksana would survive and prayed for her, offering blood, buying medicine," Mr Azarov said.

The case has caused a public outcry in Ukraine, exposing incompetence by the law-enforcement authorities and the extent of social problems in industrial cities such as Mykolayiv, which are riddled with drugs and AIDS.

Ukrainian media had alleged that the suspected attackers - two of whom were initially allowed to go free - are the sons of parents with strong connections to leading local officials.

The mother of one suspect used to be the head of a district in the Mykolayiv region, the regional interior ministry confirmed, prompting allegations the authorities had been trying to keep a lid on the whole affair.

Meanwhile, Makar's mother controversially posted a harrowing video of Oksana in hospital on YouTube where she raises up the bloodied stump of her arm and, apparently barely able to speak, says she feels "awful".

In another disturbing video that was leaked to Ukrainian media, one of the suspects is allegedly shown calmly relating to investigators how the three successively raped Oksana and then killed her when she started threatening to call police.

All three men have now been charged with premeditated rape and murder.

Authorities say several officials from the police and local prosecutors were fired and reprimanded for initially letting the suspects go free.

Originally published as Teen dies after horror gang rape