As the sun began to slip behind the verdant Manipur hills, Kolom Rabi prepared for a long night ahead. Hurriedly he slung a cartridge belt over his shoulder, strapped on a walkie-talkie and grabbed his shotgun. In the surrounding houses, dozens of his neighbours – farmers, students, teachers and office workers by day – donned their green army fatigues and picked up their rifles, before gathering in a sandbag-lined bunker on the village outskirts to await instructions. Tonight, it was Rabi’s turn to be the commander of this makeshift civilian militia.

“The Indian state has failed to provide us security so we have been protecting ourselves with our own guns for over a year now,” said Rabi. “I don’t know when this will all come to an end.”

Rabi, a member of the majority Meitei community in India’s northeastern state of Manipur, had never wanted to take up arms. A 49-year-old with a doctorate in plant genetics, his life and work had always been agriculture; that was until a bloody ethnic war came to his doorstep.

“If the government can assure us security and negotiate with us, we will leave the guns,” said Rabi. “Otherwise, for the protection of our brothers and sisters, we are ready to die and kill.”

The violence in Manipur began last May with clashes between the majority Meitei and the minority Kukis-Zo tribes over the removal of special minority privileges for the Kuki community. Since then, it has escalated into an ongoing ethnic conflict which has killed over 220 people and displaced over 60,000 as whole villages were burned to the ground, while women reported sexual assault and rape.

An unofficial border dividing the state down ethnic lines – Kuki-Zo on one side and Meitei on the other – has become a hardened frontline, created and fiercely guarded by civilian militia groups from both communities. Thousands of guns, many sophisticated rifles stolen from state armouries, are now in the hands of these unregulated vigilante civilian armies who freely mobilise every night to protect their own turf. The police and the state stand accused of being both complicit and unwilling to intervene.

Haopu Haokip, a 26-year-old from the town of Churachandpur in the Kuki-Zo territory, spends most nights clutching a shotgun, ready to shoot any “Meitei intruders”. His village was burned to the ground in the violence, killing two of his friends, and his whole family now live in a displaced persons camp.

“I picked up the gun to save my community, to defend,” said Haokip. “I do not condone violence. But after seeing my house burned down and friends killed, only this gun gives me some sort of relief.”

The Kuki-Zo side say they are now fighting for their own separate state. However the Meiteis – who dominate the government and police – have called that demand unacceptable and all talks have only led to a stalemate. Experts and civilians on the ground have warned that, as divisions between the communities become more deeply entrenched and increasingly weaponised by militants, Manipur stands on the brink of descending into all-out lawlessness.

For prime minister Narendra Modi, whose Bharatiya Janata party (BJP) also rules the state, Manipur has become a significant achilles heel for his government. He stands accused of failing to bring the conflict under control and has attracted widespread criticism from civil society groups for not visiting since violence broke out.

After the BJP lost its two Manipur parliamentary seats in the recent national election – blamed on widespread anger in both communities at how Modi’s government has appeared to ignore the conflict – the opposition Congress party have increasingly focused on Manipur as a way to attack the prime minister, accusing him of “breaking and burning” the state. Opposition leader Rahul Gandhi pointedly made his third visit last month, where he called on Modi to “listen to the people of Manipur”.

While Modi recently told parliament that a state of “normalcy” was returning to Manipur, those on the ground gave a very different story. Of particular concern to police and intelligence officials has been the return of an estimated 2,500 people from banned groups that had previously been associated with militancy and separatist insurgencies in Manipur and India’s northeast region.

These militant figures have spent years outlawed and exiled over the border in neighbouring Myanmar and Bangladesh. But according to locals and police, these groups have used the recent unrest as cover to return to Manipur and have begun re-exerting control over swathes of the state’s population using violence, extortion and moral policing. The Meitei militant groups are also accused of bringing weapons over from Myanmar, including grenades, rifles and communication equipment, and of helping to train and arm the vigilante militias to further their own agendas.

Praveen Donthi, senior analyst for India at the International Crisis Group, said interplay of ethnic rivalries combined with the return of militant groups meant that the situation Manipur had become a “tinderbox” that was “fast becoming a regional conflict”.

“The Meitei insurgent groups based in Myanmar, who were at their weakest before May last year, have seen a resurgence, probably beyond their wildest expectations, due to the current conflict in Manipur,” said Donthi. “The insurgent groups and separatist tendencies are strengthening every day.”

Kennerich, a Meitei civil society leader who uses a single name, warned of “catastrophic violence and escalation in civil war” if the increasingly destabilising presence of these militant groups in Manipur was not brought under control by the state. In Bishnupur, along the highway that connects Manipur with the rest of India, militants have set up checkpoints where they are accused of extorting money from drivers in the name of providing security.

Those on both the Kuki-zo and Meitei and sides, including the state’s small Muslim Meitei minority, also accused militants of visiting homes and extorting billions of rupees from locals at gunpoint. Those who refused to pay the ransom have allegedly been tortured with methods such as hot coals being placed on their skin, with video footage of one incident shown to the Guardian. Several Meitei women also accused the militants of moral policing, with women harassed and beaten up for reasons like “not wearing proper clothes” and “having a boyfriend.”

Commanders of two outlawed militant outfits, both aligned with the Meitei community, confirmed they had returned from Myanmar soon after the violence last May. “We came back at the request of our people. They have no trust in the government, and that is why they want us to protect them,” said one commander, speaking to the Guardian from a discreet location in Manipur under the condition of anonymity. They denied all charges of extortion, claiming they were taking “donations being given wilfully by supporters”.

In an interview with the Guardian, BJP chief minister of Manipur, Nongthombam Biren Singh, confirmed that the presence of organised militant groups was a major concern for the state’s security situation, but denied that any new militants had crossed back over the border since the violence began.

Singh, who recently met with Modi for the first time in over a year to discuss the situation in Manipur, admitted he was “struggling” with the restoration of peace amid an ongoing stalemate and endless failed negotiations. Singh and his BJP government are seen to be aligned with the dominant Meitei community and have been accused by human rights groups of protecting and giving a free hand to several Meitei militant groups associated with atrocities committed against the Kuki-Zo community.

Singh also defended allowing armed civilian militias to flourish and become the de facto law and order authority of the state, stating they had become a necessity as “we do not have adequate numbers of police and paramilitary personnel who can help prevent and protect from the attacks of the militants.”

For the tens of thousands living in displacement camps, from both the Meitei and the Kuki-Zo communities, the continued stalemate and enduring violence has left them in a state of purgatory and the feeling of being abandoned by the Modi government was rife. Frustrations began to boil over this month when almost a hundred displaced people living in Akampat relief camp held a protest at their conditions, with police firing tear gas at them in response.

Ngaithenhoi Haokip, 27, from the Kuki-Zo community, said her family was barely able to survive in the camps after their village was scorched by a Meitei mob in May last year, leaving them with nothing. “There is no way to earn any money,” she said. “There is no food for my children, and they often get sick but I can’t afford to take them to a doctor.”

For 26-year-old Meitei Loitongban Nainao, also displaced to a camp after his home was burned down, said the situation was so bleak he recently attempted to take his own life. “This life is meaningless and frustrating,” he said. “I do not know when we can return to our village. It is like living in jail.”