The Rohingya Muslims launched the attack at the immigration centre on Sumatra island using weapons fashioned from smashed up beds and broom handles after seeing pictures of religious violence in Myanmar last month that left dozens dead.
The attack underscores the soaring Muslim-Buddhist tensions that have cast a shadow over political reforms in Myanmar, where the end of decades of authoritarian military rule has laid bare deep sectarian fault lines.
Last month's disorder was the worst since an eruption of violence between Buddhists and Rohingya Muslims in the western state of Rakhine last year that left scores dead and tens of thousands - mainly Muslims - displaced.
An increasing number of Rohingya - viewed by many Burmese as illegal Bangladeshi immigrants - have been arriving on Indonesian shores.
Immigration centre official Rida Agustian said the entrance to the block where the detainees were being held was sealed off to stop officers from intervening as the deadly attack was launched in the early hours.
When officers finally got in, they found "blood spattered on the walls and in pools on the floor," he said.
"The men had used wood from their beds and broom sticks as weapons to kill.
"The bodies were covered in blood, it looked like they were beaten and tortured to death."
Agustian said 15 people, believed to Rohingya, were injured during the violence at the centre, where 106 of them are being held.
Kyawkyaw, 25, who gave only one name and is one of a handful of Myanmar Buddhists being held at the centre, said he heard the attack unfolding and was "very scared".
"We ask the Indonesian government to send us straight back home to Myanmar," he told AFP outside the centre before being taken away for questioning by police.
He said the victims were from a group of Myanmar Buddhists being held at the centre at the port of Belawan after being caught illegally fishing in Indonesian waters, and had been due to be deported next month.
The attack began after the detainees saw images of recent violence between non-Rohingya Muslims and Buddhists in central Myanmar that has left at least 43 people dead and many Muslim homes and mosques destroyed, said local police chief Endro Kiswanto.
"They managed to see some photos of the violence in Myanmar, including buildings on fire, and we believe that's when the violence broke out," Kiswanto told AFP.
He said all eight Buddhist men were dead when police arrived at the detention centre in the early hours of Friday morning.
Twenty-five detainees and 30 other witnesses were being questioned by police, and 30 officers were at the site, Kiswanto said.
Many Rohingya Muslims arriving on Indonesian shores face long stints in detention awaiting UN assessment for refugee status. Myanmar views its population of roughly 800,000 Rohingya as illegal Bangladeshi immigrants and denies them citizenship.
Last month's communal violence was apparently triggered by an argument in a gold shop in the central town of Meiktila that turned into a riot, but witnesses say the wave of violence since then appears to have been well organised.
Human Rights Watch (HRW) this week urged Myanmar to investigate the failure of police to stop the violence.
"The government should investigate responsibility for the violence in Meiktila and the failure of the police to stop wanton killings and the burning of entire neighborhoods," said HRW Asia director Brad Adams.
COMMENTS (12)
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I think this incident act as a "fuel of fire" in Myanmar and Srilanka. Praying from ALLAH (S.W.T.) that it is not going to happen.
Gulam Rasool"Kuldeep sharma" New Delhi
Actually this news in not 100% valid. The attack happened because of the budhist did sexual harrashment to the muslim women and the rohingya's tried to protect them... I dont really get it why every western news always turning the fact especcially if it is related to Muslim!
@Stranger: "@heera: I am a Hindu myself but why drag Hindus in this issue. We have nothing to do in this case." I am an Hindu myself and both of us and the world know how Hindus seek lollipops of "shabaash" on their backs. It is pathetic!
@mes: @Yuri Kondratyuk
When your family is killed by a group of people and they are in the same room with you, you can kiss their faces to show your 'tolerance'. We will see how much love you will pour to the killers of your loved ones.
@heera: I am a Hindu myself but why drag Hindus in this issue. We have nothing to do in this case.
Hmmm something calculated and planned and operated meticulously cant be a clash. Its a a cold blooded murder.
Bangladesh is over populated, spilling into Myanmar. With Myanmar border being porous and border guards corrupt, Bangladeshi immigrants are crossing over to Myanmar and occupying illegally. They are desperate and will do anything to grab new lands. Look at those people, they don't look anything like Myanmar people. They belong in indian subcontinent with their own people.
I wonder why the Rohingyas aren't the best loved human beings of all!
Some people may not agree with me,But Hindus r most tolerant lot among all the religion.See the history of all religion and their violence record.
It's time we use subjects & projects in colleges & universities to study about reasons that turn believers into coldblooded killer. Is it their teaching, belief, modern technology, lack of jobs, facilities, resources, corruption, incompatable laws, dictatorships, market trend, food resources, overpopulation, desire of bigger religious funding or donations base, fast changing world,free women or simply racism & desire ethnic purity that's feeding this monster? Extra bonus projectz or thesis work will really help this cause. We defenitely need hard working tea her teachers & professors.
This is not a clash. Looks more like murder.