Ghaziabad (UP) | Three sisters, the youngest just 12, allegedly addicted to an online Korean game that involved a series of tasks, died after jumping off the balcony of their ninth-floor home in the early hours of Wednesday, police said.

Nishika (16), Prachi (14), and Pakhi left behind a chilling note that said, "Read everything written in this diary, it is all here " It was accompanied by a crying face emoji and a handwritten message, "Sorry papa, I am really sorry."

The diary was recovered from the girls' belongings. The three did not go to school and had been home for the last two years, police said.

Their father, Chetan Kumar, a forex trader, has two wives, both sisters, and there were five children in all - four daughters and a son. The entire family lived together.

Police received information that three girls had jumped from the balcony of their home in Bharat City in Sahibabad area in Ghaziabad, the busy satellite town abutting the national capital, around 2.15 am.

Investigation revealed that two sisters jumped together, holding each other's hands, while the third jumped off alone from the window of the prayer room, police said.

They were rushed in an ambulance to a hospital in Loni, close by where doctors declared them dead on arrival, the tragedy jolting the middle-class neighbourhood and highlighting the perils of online addiction and the impact on young minds.

Uttar Pradesh Director General of Police (DGP) Rajeev Krishna told PTI in Lucknow, "We are getting the whole case examined in detail."

The state police chief also stressed the need for cyber awareness, saying the police department holds regular awareness drives, and people can reach out to local police stations for issues related to online addiction.

Though details were sketchy, Deputy Commissioner of Police Nimish Patil said preliminary investigation revealed the girls were influenced by Korean content and spent a significant amount of time on their mobile phones.

He said the girls' education had been irregular and their academic performance was below par.

"But it is evident that the girls were highly addicted to mobile phone usage," he said.

Assistant Commissioner of Police (Shalimar Garden) Atul Kumar Singh added that the sisters were addicted to a Korean task-based interactive "love game".

"Their parents had restricted their mobile phone usage for the past few days, which left them distressed. This may have triggered the decision (to take the extreme step)," he said.

The sisters got addicted to online gaming during the pandemic years and played it almost without a break. They had been playing the game for the last two-and-a-half to three years, said the father.

His face masked and his voice tearful, Kumar said he was unaware that the game involved tasks. He also added that his daughters had repeatedly said they wanted to go to Korea.

"They often said they wanted to go to Korea. I did not know that this game involved such tasks. I came to know about all this only after the police forensic team examined their mobile phones," Kumar told PTI.

"If I had known that such tasks existed, I would have stopped it. No father would ever allow his children to be part of it," he said.

Recounting the sequence of events, Kumar said the family was asleep at the time. "My wife was sleeping in the inner room. The girls woke up on the pretext of drinking water, bolted the door from inside and jumped from the balcony."

He said the girls threw their mobile phones outside the room. "The police later seized them for investigation."

According to Kumar, Prachi, the middle sister of the three, once told him she was the 'boss' and that her sisters followed her directions.

Kumar said the three sisters did everything together -- eating, bathing and spending time -- and mostly remained confined to their room.

He added that the girls had not attended school for the past two to three years after their academic failures. This made them feel embarrassed and increasingly withdrawn.

Police said that Kumar had moved to the Bharat City housing society in Ghaziabad with his family around three years ago.

During the investigation, police found that Kumar's first wife could not conceive, which caused marital discord. With the wife's consent, he then got married to her younger sister, a police official said.

"After the second marriage, the couple was blessed with a daughter. In a surprising development, the first wife also gave birth to children later, an official said.

Police said the first wife gave birth to two children, while the second wife had three. The youngest sister of the two wives was staying at the apartment with the family on the night of the incident, they said.

"When we are looking at gaming, what has also been identified is that instead of the real identity, a lot of adolescents these days identify themselves more with their gamer identity or the avatar that they take on. And so, their entire psyche is moving around their competency in that game rather than in real life," Mumbai-based forensic psychologist Deepti Puranik told PTI.

A neighbour standing on his balcony saw the horror unfold.

"I live on the 10th floor in the tower facing the girls' tower. Around 2 am, I was standing on my balcony before going to bed, and I saw the oldest girl sitting on the ledge of the window that covered their balcony on the 9th floor in the opposite tower. The sliding panel of the window was open, she was facing the room and had her back towards me. She appeared to be rocking back and forth while sitting on the window frame,” Arun told The Indian Express.

"As I watched, it appeared that the second sister was hugging the older sister, and they were rocking together. Suddenly, the older sister toppled backwards and fell through the window, and the second sister came with her. The youngest sister, who too was at the window, appeared to lunge forward to catch them, but she too fell through the opening," he added.

The apparent suicide pact recalled the Blue Whale challenge that is believed to have pushed a 14-year-old Mumbai boy to suicide in 2017. It was a 50-day challenge believed to have originated in Russia and claimed over 130 lives across Russia and the Central Asian countries of Kazakhstan and Kyrgyzstan.

It gave a task a day -- each one potentially fatal -- to the player for 50 days.