The dead were identified as belonging to Punjab province. No group has claimed responsibility for the attack so far.
Armed vigilante groups have been taking the law into their own hands in parts of Manipur, in the wake of ethnic rioting earlier, thus complicating the peace process. At times, militant groups have joined in the fray, creating an even more volatile cocktail of ethnic tension.
They said information has been circulated throughout all formations to ensure that the Manipur Police Commando uniform, black in colour, is not misused and they have been instructed to intensify the vigil.
The CBI has arrested from Pune a 22-year-old man suspected to be the mastermind behind the case of two missing Manipuri students who were believed to have been killed, officials said.
The four, including the wife of the main accused, were taken 'outside the state' by a special flight, Singh said.
The security agencies have been warning that militants belonging to United National Liberation Front, People's Liberation Army and other banned groups had become part of the mobs and carrying out sneak attacks on security forces as well as giving directions to the agitators.
The Manipur Police personnel allegedly drove the two women from the Kuki-Zomi community, who had sought refuge in their official Gypsy, to a mob of around 1,000 Meiti rioters in Kangpokpi district, the Central Bureau of Investigation chargesheet has said.
The ITLF alleged that thousands of weapons looted from state armouries in capital Imphal are being used in the "ethnic cleansing campaign".
The house of Manipur PWD Minister Konthoujam Govindas in Bishnupur district was vandalised on Wednesday by a group of people claiming that the government in the strife-torn state is not doing enough to protect locals from militants belonging to another community, officials said.
The agency filed the charge sheet against six people and a report against one child in conflict with the law before a special CBI court in Guwahati, nearly three months Manipur Police made arrests in the case.
This comes after 10 Kuki MLAs, cutting across party affiliations, had expressed their inability to attend the assembly session as violence in the northeastern state continued.
Ten Manipur tribal MLAs Thursday urged Prime Minister Narendra Modi not to withdraw Assam Rifles from security duties in the violence-hit state, saying its personnel have been putting their lives at risks to create buffer zones between the two warring communities.
Known as 'Sentinels of the North East' and 'Friends of the Hill People', the officers, drawn from the Army, and jawans have been fighting a war of nerves since the ethnic clashes between majority Meitei and hill tribe Kukis erupted on May 3.
The Supreme Court on Wednesday protected four members of the Editors Guild of India against any coercive action till Monday in connection with two FIRs lodged against them in the state for offences, including promoting enmity between two communities.
The surrendered weapons included self-loading rifles, carbine, AK and INSAS rifles, light machine guns, pistols, M16 rifles, smoke gun/tear gas, sten gun and grenade launcher.
The Centre is working on a three-pronged approach to bring the warring Meitei and Kuki communities into a narrow common ground for lasting peace in trouble-torn Manipur, sources said on Wednesday.
Sub-divisional police officer Chingtham Anand, a resident of Imphal's Haobam Marak locality, was killed in a sniper attack while he was on duty overseeing the cleaning of the grounds of Eastern Shine School for construction of a helipad jointly by the police and BSF, officials said.
He also held another meeting with a delegation of civil society organisations as part of his outreach and they expressed their commitment to peace and assured that they would work for restoring normalcy in Manipur.
Manipur Chief Minister N Biren Singh on Wednesday appealed to people to surrender weapons looted from security forces and warned of legal action against anyone found to be in unauthorised and illegal possession of arms and ammunition.
The lawlessness because of the fake picture spread like jungle fire and was one of the reasons for the state government to shut down the Internet on May 3, the officials said.
In most parts of the landlocked northeastern state, items such as rice, potato, onion and egg besides LPG cylinders and petrol are selling at rates much above the ones fixed by the government.
Business establishments remained closed on Tuesday morning and people were asked by security personnel to remain indoors through the public address system in New Chekon area of Imphal East district, where a mob torched two houses after four armed people, including a former MLA, forced people to shut their shops on Monday.
Manipur Chief Minister N Biren Singh on Monday said that a police case has been filed on the basis of a complaint against the president and three members of the Editors Guild of India (EGI) for a report critiquing media coverage out of Manipur, and accused them of trying to "provoke clashes" in the state.
In fresh violence in Manipur, two houses were torched by a mob in Imphal East district after two armed miscreants forced people to shut their shops on Monday afternoon, police officials said.
Manipur Police has registered a first information report (FIR) accusing the Assam Rifles of blocking their vehicle after an altercation between the two groups last week, while the state unit of the Bharatiya Janata Party requested Prime Minister Narendra Modi to replace Assam Rifles 'by any other paramilitary force permanently' from the state.
The video, which drew widespread condemnation, shows the men constantly molesting the two helpless women, who cry and plead with their captors to spare them the horror.
Quoting data collected from various sources, officials closely monitoring the situation here said that .303 rifles, Medium Machine Guns (MMG) and AK assault rifles, carbines, Insas Light Machine Guns (LMG), Insas rifles, M-16 and MP5 rifles were reported to be missing from the armouries of the police in May.
Parents of both the murdered youths, viral pictures of whose bodies caused widespread protests in Imphal valley for two days, on Thursday pleaded with authorities to locate the remains of their children so that the last rights of the boy and the girl can be conducted 'with the dignity they deserve'.
In a memorandum submitted to Manipur Governor Anusuiya Uikey, the 21 opposition MPs who signed the document demanded urgent rehabilitation and resettlement of the affected people to bring peace and harmony to the state.
Over 1,300 people signed the open letter within 48 hours, which was submitted to the Prime Minister's Office on Monday.
The Supreme Court on Friday said the trial in the Manipur violence cases being probed by the Central Bureau of Investigation (CBI) will take place in neighbouring Assam and asked the Chief Justice of the Gauhati high court to nominate one or more judicial officers to deal with the matters.
The proceedings began at 11 am with two-minute silence for those killed in the ethnic violence between Meiteis and Kukis that began on May 3.
Hours before a planned mass burial of Kuki-Zomi people killed in Manipur's ethnic violence, the state's high court on Thursday ordered that status quo be maintained at the proposed burial site in Churachandpur district, while ITLF, an apex tribal body also said it was postponing burial service plans following requests from the Union home minister.
We are a "people's court" and giving a hearing is part of the healing process, the Supreme Court said on Monday while asking the members of the bar in violence-hit Manipur to ensure no lawyer is denied access to the court proceedings in the state.
However, official sources said the Assam Rifles -- a border guarding force -- primary mandate or task is not drug law enforcement.
The ATRs have been sought on a range of matters within four weeks, the officials said.
Observing that it does not propose to run the administration in Manipur, the apex court said necessary verifications shall be carried out before issuing the Aadhaar cards expeditiously.
In a separate incident, a tribal woman had lodged a complaint at Saikul police station, stating that her 21-year-old daughter and her 24-year-old friend were allegedly raped by a mob at their rented house near Konung Mamang before brutally murdering them on May 4.
A bench comprising Chief Justice DY Chandrachud and Justices JB Pardiwala and Manoj Misra also took note of the affidavit of the Manipur chief secretary that there was no short supply of basic commodities like food and medicines for people facing economic blockade.
The fighting started after the PDF attacked two military bases at Khawmawi and Rihkhawdar in Chin state near the Indian border, he said, adding that the fighting continued till Monday.