LUCKNOW (AFP) - Indian police have arrested two men over the gang rape of a teenage girl whose body was found hanging from a tree, a senior officer said on Monday (May 30), a grim reminder of a similar case in the same state.

The girl, reportedly 15 and from one of India's low social castes, was strangled - allegedly by three men - last Friday night outside her village in the northern state of Uttar Pradesh.

Her body was found the next morning hanging by her scarf from a tree about a kilometre from her home in Bahraich district, said police Superintendent Salik Ram Verma.

Two men were arrested and "the third accused is on the run", Supt Verma told AFP.

The girl had left her sleeping family to secretly meet one of the men, only to discover that he had brought along two of his friends who attacked her.

"When the girl resisted their bid, she was raped and later strangled. To make it look like a case of suicide, they hung her body from a tree and left the spot," Supt Verma told AFP.

Four local police constables have also been suspended after an initial lack of action over the incident sparked outrage among villagers.

"I have suspended four constables for laxity and have issued stern instructions to the inspector concerned to book the third accused soon," Supt Verma said.

"The medical report has confirmed rape and strangulation," he added.

The case comes two years after two girls from a low caste were found hanging in a village in Uttar Pradesh. Their families said they had been gang-raped before being lynched.

The families said the cousins, aged 12 and 14, had been attacked after they went outside after dark to relieve themselves because their ramshackle homes did not have a toilet.

The case sparked a political row after federal investigators concluded the girls had committed suicide and were not raped.

It also reignited anger about high numbers of attacks against women, after the public outrage that erupted over the fatal gang rape of a student in Delhi in 2012.

That incident sparked tougher punishments for rapists and improved policies for police handling of assault cases, to try to encourage more victims to report the attacks.