The exploding smart phone batteries that forced Samsung to scrap its top-end Galaxy Note 7 were installed in a factory in rural Vietnam overlooking buffalo fields and rice paddies where workers earn salaries starting at £33 a week, MailOnline can reveal.

Batteries were processed and packaged in Samsung's specialist SDI battery-making plant in northern Vietnam where the South Korean giant phone maker has invested billions of pounds since 2009 to create a low-cost global production hub.

Nearly 50,000 workers from some of Vietnam's poorest towns and villages work up to 12 hours a day in the vast Samsung complex built amid farmland with one of Southeast Asia's cheapest labour markets.

And while Samsung insists it will not axe jobs in Vietnam this year because of the scandal, workers in the battery factory within the complex say the company has already started temporary lay-offs.

The exploding smart phone batteries that forced Samsung to scrap its top-end Galaxy Note 7 were put together in a factory in rural Vietnam overlooking buffalo fields and rice paddies

Workers say the batteries were processed and packaged in Samsung's specialist SDI battery-making plant in northern Vietnam. Picured: Local market next to sprawling complex

Investigators are examining procedures at the Samsung SDI plant in Bac Ninh (pictured) – 40km north of Vietnam's capital Hanoi – to find the cause of the catastrophic blazes

Samsung recalled 2.5 million smartphones after some 25 cases of Note 7 smart phones bursting into flames. The Note 7 has now been scrapped altogether

The enormous plant is 40km north of Hanoi (above) and has tripled the province's GDP in four years

Investigators are examining procedures at the Samsung SDI plant in Bac Ninh – 40km north of Vietnam's capital Hanoi – as they try to find the cause of the catastrophic smart phone blazes, factory insiders told Mail Online.

'We're all very worried for what the future holds,' said a 23-year-old woman production line worker who been at the SDI factory within the Bac Ninh complex for two years.

'Officials have been all over the place in the past few weeks and our Korean managers seem on edge.'

Galaxy Note 7 smart phones – which retailed in the UK for around £749 – were made at Samsung's two Vietnam factory complexes in Bac Ninh and Thai Nguyen as well as in South Korea and China, while the batteries were packaged at Bac Ninh, workers said.

We're all very worried for what the future holds. Officials have been all over the place in the past few weeks and our Korean managers seem on edge. Production line worker at Samsung SDI

The cells for the batteries – designed to drive the Note 7's high-end features including an iris scanner and fast wifi charging – were made in one of Samsung SDI's battery manufacturers in Korea, China and Malaysia, but the company refused to divulge which one.

From there, the cells were then sent to Samsung SDI in Bac Ninh to be processed and packaged ready to fit into the devices.

The battery cells were fitted into a 'mould' or frame to make them compatible with the smart phones before being sealed up and placed in the phones.

The batteries were then put into the phones in another part of the sprawling Bac Ninh complex.

Samsung says it will not axe jobs in Vietnam because of the scandal, but workers say temporary lay-offs have already started. Pictured: Third floor of complex appears shut down

Nearly 50,000 workers from some of Vietnam's poorest areas work up to 12 hours a day in the vast Samsung complex built amid farmland. Pictured: Employees leaving at the end of the day

A spokesman for Samsung denied that workers at Samsung SDI had been laid off : 'We maintain the same number of employees as before the Note 7 issue'. Pictured: Workers leaving at the end of the day

Samsung recalled 2.5 million smartphones after at least 25 cases emerged of the Note 7 smart phones bursting into flames. The model was scrapped altogether after replacement phones began catching fire too.

Five replacement phones have reportedly caught fire in the US. In one incident passengers were evacuated from a Southwest Airlines flight in Kentucky when a replacement Note 7 started smouldering and making popping noises.

Another Note 7 phone was believed to have caught fire on a flight from Singapore to Chennai in India, prompting the government to summon Samsung officials to a meeting.

Samsung SDI is a division of Samsung specialising in batteries but operates as a separate listed company.

The Vietnamese factory, which also makes batteries for other models and brands, was still operating this week.

But windows on the third floor where workers said the Note 7 batteries were handled were shuttered and unlit as work continued into the evening on other floors.

'We don't know what's happening but some of my colleagues have been sent home on 70 per cent pay and told to wait until more work comes in,' one worker told MailOnline.

Factory workers said they were warned by management not to speak about the issues inside the Samsung plant. Pictured: Shops and restaurants opposite the Bac Ninh complex

But windows on the third floor where workers said the Note 7 batteries were handled were shuttered and unlit in the evening. Pictured: Gates at the vast complex

In Bac Ninh alone, more than 2,000 new hotels and restaurants opened between 2011 and 2015 because of Samsung's arrival. Pictured: A local market next to the complex

Production line jobs at the Bac Ninh factory pay a minimum of 4 million Vietnam dong (VND) a month (£147) – above the regional minimum wage of 3.5 million Vietnam dong. Pictured: Coach park at factory

Samsung has invested £12.3 billion in Vietnam since it began operations there seven years ago and directly employs around 130,000 people across the country with another estimated 270,000 jobs relying on Samsung. Pictured: One of the many entrances to the factory

Factory workers said they had been expressly warned by management not to speak to anyone about the issues inside the Samsung plant and all spoke on condition of anonymity.

The initial explosions in Galaxy Note 7 phones are said by Samsung to be caused by a flaw in the battery cell – a high-powered battery designed to drive the phone's sophisticated features including an iris scanner and fast-charge technology.

Production line jobs at the Bac Ninh factory pay a minimum of 4 million Vietnam dong (VND) a month (£147) – above the regional minimum wage of 3.5 million Vietnam dong.

With overtime, however, most workers say they collect monthly pay packets of around 8 million VND (£295) with higher skilled workers earning up to 12 million VND (£442.50).

'It's hard work and the hours are long but it's very good money for this part of the country,' said a 20-year-old male worker who moved 100 miles from Vietnam's border with China to live and work at the factory.

Samsung's share price was hit particularly badly when the company announced the complete recall of the Galaxy Note 7

Shortly after recalling the Note 7, Samsung sent out special fire resistant boxes for customers to return their handsets. The kits (above) contain a series of boxes, protective bags and gloves

The initial explosions in the Note 7 are said by Samsung to be caused by a flaw in the battery cell. Pictured: Customers have shared photographs claiming to show their burned handsets

Customers with Note 7 devices should turn off the power and seek a refund or exchange them. Pictured: A car on fire in the US which allegedly started after a Note 7 was left on charge

Samsung has invested £12.3 billion in Vietnam since it began operations there seven years ago and directly employs around 130,000 people across the country with another estimated 270,000 jobs relying on Samsung.

In Bac Ninh alone, more than 2,000 new hotels and restaurants opened between 2011 and 2015 because of Samsung's arrival and the province's GDP soared to three times the national average.

I've heard their scientists have already finished the Galaxy 8. We'll start making it in a few months and there'll be more work than ever and all this fuss will be forgotten. Factory worker

The Bac Ninh complex made 100 million products last year which generated £10.4 billion in overseas sales, accounting for more than 11 per cent of Vietnam's total export turnover.

The Korean electronics giant is now Vietnam's biggest single exporter, exporting £27 billion of electronics in 2015 alone.

The exploding smartphone scandal has raised severe questions about the prospects not only for Samsung but for Vietnam's national economy.

Social media users joked about the danger of the beleaguered Galaxy Note 7

Social media users have been posting jokes about the Note 7 since the scandal broke. One person quipped that Note 7 users could end up like Two-Face from the Dark Knight

But on Wednesday evening as they ate noodles and drank beer in the migrant workers' shanty town that has sprung up alongside buffalo fields outside the vast Bac Ninh complex, employees were confident Samsung would bounce back.

'There was nothing here before Samsung came along,' one 27-year-old worker from a local farming family said. 'They're brilliant business people and they'll soon get over this setback.

'I've heard their scientists have already finished the Galaxy 8. We'll start making it in a few months and when that happens, there'll be more work than ever and all this fuss will be forgotten.'

A Galaxy Note 7 burning at a Burger King in South Korea was apparently caught on video by someone eating at the fast food restaurant

Employees are confident Samsung will survive: 'I've heard their scientists have already finished the Galaxy 8. We'll start making it in a few months and... all this fuss will be forgotten'. Pictured: A Note 7 customer posted an image claiming to show their burnt out phone

A spokesman for Samsung denied that workers at Samsung SDI had been laid off as a result of the problems with the Note 7.

'We maintain the same number of employees as before the Note 7 issue,' he said in an emailed response.

Asked what the nature of the investigation at the Samsung SDI factory in Bac Ninh was and what it had established so far, he responded: 'No comment.'