A shooter takes aim at a line of unsuspecting cars filing along the main road into Rio de Janeiro in a scene that should terrify every athlete and visitor to the Olympics this summer.

The road is the Red Line, Rio's main highway and the only route into Brazil's Olympic city along which will every sports fan, athletics delegation and foreign dignitary will travel to get to the mega-event.

The 13-mile express way runs from Rio's international airport into the city, and is in the most part lined with sprawling favela shanty towns which are dangerous no-go zones controlled by heavily-armed drugs gangs.

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An image has emerged of a shooter aiming a semi-automatic rifle at passing cars on the only route that will take athletes and sports fans from Rio's international airport to the Olympic Village when the Games begin in August

A previous shoot out on the Red Line express way in Rio showed people cowering next to the cars in a bid to avoid the bullets

A man, appearing to hold a small baby, runs for cover during an gang violence on the main access road from Rio international airport to the the Olympic Village

With just seven weeks to go before the Olympic party kicks off, the image - posted by bragging bandits on social media yesterday - shows that, despite promises to clean up the city's crime-ridden slums, gangsters appear to be still firmly in control.

Experts expressed amazement at how the gangs could get hold of what appears to be an AR-15 gun, complete with a state-of-the-art holographic sight, which even the Brazilian army don't possess.

Most alarmingly, though, with the favelas out of bounds, even for the police, the shooter and his powerful weapon may still be there when VIPs and sports stars start arriving for the Games.

In recent months, a sharp rise in violence in Rio's favelas, fuelled by Brazil's economic and political crisis, has increasingly spilled out onto the city's main access road, which passes just metres from the slums on its way to the famous beaches and hotels.

Several terrifying incidents along the Red Line in recent months are causing panic even among Rio residents used to high levels of violent crime in the city.

They include car jackings and even hostage takings, while almost daily shootouts between rival gangs, or ferocious battles with the police, have left road signs and barriers pockmarked with bullet holes - and motorists fearing for their lives.

A man lies on the ground during a shooting by gang members on the road, which will take athletes and sports fans from the international airport in Rio to the Olympic Village and the city's famous hotels and beaches

Last month, a 17-year-old girl died after being hit in the head by a stray bullet as she sat in the back seat of a car being driven along the freeway to the international airport to meet her mother, who was arriving in the city on Brazil's Mother's Day.

And earlier this month, 27-year-old psychologist Anna Paula Cotta was also shot in the head by gangsters robbing motorists on a slip road to the Yellow Line, another expressway which takes drivers from the Red Line to the Barra da Tijuca district, site of Rio's Athletes Village and Olympic Park.

The woman, a successful target shooter, was operated on and is now in a stable condition in hospital.

In April, Brazilian congressman Aureo Lidio Ribeiro and a friend were kidnapped at gunpoint, tied up, then dumped on the Red Line by gangsters who stole the Jeep he had been driving.

And last month, a gang was caught who would kidnap motorists driving along the Red Line and hold them captive in a house inside the nearby favela, while the criminals would use the victims bank cards to withdraw money and make purchases, before eventually setting them free.

Meanwhile, MailOnline has spoken to a slum dweller who claims he recently saved a foreign tourist from being executed by gangsters after he took a wrong turn in his hire car while returning along the Red Line to the Tom Jobin international airport and entered the favela by mistake.

Others are not so lucky. In October last year, when pensioner Francisco Murmura, 69, was sent into another favela while following his mobile phone navigation app Waze, traffickers sprayed his car with bullets, killing his 70-year-old wife Regina.

In recent months, a sharp rise in violence in Rio's favelas, fuelled by Brazil's economic and political crisis, has increasingly spilled out onto the city's main access road. Pictured are a group trying to take cover from a hail of bullets

And in 2013, engineer Gil Barbosa, 53, was shot dead by bandits when, as he was driving to the airport to pick up his wife, she called to tell him she had taken a taxi home and he left the express way to turn round and return home, only to drive into the gang-controlled Complexo da Maré favela.

Recent footage and photos of terrified motorists cowering behind their vehicles, while bullets whizz past their cars as police battle with traffickers in broad daylight, will do little to reassure Olympic visitors and athletes they will be safe during their stay in Rio.

With the Games just around the corner, there are currently no fewer than 15 separate gang wars taking place simultaneously across Rio de Janeiro, according to a recent study, which have turned at least 15 different slum districts into conflict zones.

Yet Brazil's economic crisis has meant that spending on security in Rio has been cut by a massive 35 per cent, drastically weakening the police's ability to fight the heavily-armed trafficking gangs.

In March, Rio's state security secretary Jose Beltrame admitted that spending on security in Rio was down to 'almost zero.'

Thirty-five policemen have been killed and 161 wounded in Rio's slums already this year. In 2013, 14 policemen lost their lives during the whole year.

Rising safety concerns have also led foreign embassies to warn their citizens to stay clear of Rio's favelas, where until several months ago tourism was booming.

Barriers along the side of the express way are riddled with bullet holes from shootings between rival gang members

A house overlooking the Red Line, which also has evidence of the frequent gun battles, that take place in the area

Australia's Olympic Committee have also banned their athletes from entering shanty areas, which until several months ago were almost compulsory stop-offs for visiting celebrities.

But no visitors to Rio can avoid travelling on the Red and Yellow Lines, the only access route to Rio's beaches, hotels and Olympic venues, which snake above or alongside some of the city's most notorious slums.

As the escalating violence increasingly spills out onto the tarmac, MailOnline spoke to those affected - on both sides of the barriers.

For those arriving for the first time in Rio de Janeiro, the five-mile stretch of the Red Line, hemmed in on both sides by makeshift brick shanty homes, makes for a nervy introduction to the so-called 'Marvellous City'.

Evidence of frequent gun battles are everywhere, with many houses overlooking the road, as well as concrete divides and plastic barriers erected between the road and surrounding slums, perforated with bullet holes.

Traffic on the four-lane highway often slows suddenly to a halt, sometimes by the weight of traffic, but increasingly because of the actions of criminals, fleeing the police or brazenly holding up motorists at gunpoint in their cars.

Few are in a better position to bear witness to the violence than the street vendors who sell food and drinks to motorists on the express ways when traffic becomes congested.

The Red Line road passes over a favela in the Brazilian city, which has seen escalating violence in recent months

Water seller Tiago Lima, who works along the Red Line, said moments of terror on the road from gun battles were 'constant, 24 hours a day'

Tiago Lima, who sells water along the Red Line, close to the Complexo da Maré, said moments of terror on the road were 'constant, 24 hours a day.'

But for poor slum dwellers on the other side of the barriers, though, there is no escape from the escalating violence.

Severino Jesus da Silva, 68, has for 51 years lived in a shanty shack underneath the Red Line, in the sprawling Complexo da Maré slum.

But he says that over the last few months traffickers have tightened their grip on the community, expelling rival gangs and police invasions in almost daily gun battles.

The sprawling slum, home to 130,000 people, had been earmarked for the installation of the city's next Police Pacification Unit, but budget cuts now meant the planned military occupation and re-taking of the favela from the gangs had been cancelled.

Father-of-two Severino said: 'When the bullets start flying you can't leave your home. Sometimes it starts and goes on for 24 hours.

'There have been times I've been locked inside my house for three days fearing for my life. If the people driving up there think things are bad, they should try living down here.'

Severino claims that, late last year, he came to the rescue of a foreign tourist who had mistakenly left the Red Line on the way to the international airport and driven into the favela.

He said: 'The men were pointing their guns at him and about to pull the trigger. He didn't speak any Portuguese and was terrified.

Local tourist guide Cleber Araujo, pictured, says he thinks Rio is far too dangerous for tourists to be visiting

Severino Jesus da Silva, who says he came to the rescue of a foreign tourist who had mistakenly left the Red Line on the way to the international airport and driven into the favela

'I stepped in and said I knew the guy, that he was a friend of mine and he'd come to visit me. I put him in my car and took him to the main road on the other side of the favela and called him a taxi.

'He was so grateful because he knew that if I'd saved his life. He hugged me and gave me 40 dollars.

'My advice to people coming for the Olympics is this: start praying that God will protect you, as soon as you step out of the airport.'

Recent tragic events have left even the most hardened Rio de Janeiro motorists feeling that, even on the simplest trips, they are taking their lives in their hands.

On May 7, the day before Mother's Day in Brazil, Ana Beatriz Frade, 17, was being driven to the airport by her uncle to surprise her mother, who was arriving at Rio's international airport.

Adenise Moraes da Silva, who lives in one of the favelas warned athletes and sports fans that Rio is 'too dangerous'

But gangsters from the adjacent favela were holding up motorists along the stretch of the Yellow Line they were travelling, and opened fire when Beatriz's car failed to stop, and one of the bullets hit her in the head killing her instantly.

One of Ana Beatriz's best friends, Brunela Maceldo, 18, told MailOnline: 'Bia was such a happy, positive person, always smiling and always helping anyone who needed it. She was taken away from us so pointlessly.

'Brazil finds itself in a lamentable situation, we don't have security any more, and it doesn't matter how many people died every day, it seems that the police are no longer in control.

'We all know that what happened to Bia, could happen to any one of us.'

In March this year, a police car sprayed with 12 bullets and one officer injured in a shoot out amidst heavy traffic on the Red Line at 6.40am, as police fought a gang driving two stolen cars.

And in January stray bullets fired during a shootout between two gangs in the Maré favela hit a packed bus passing by on a main road close to the Yellow Line.

Passenger José Carlos Santos, 51, a security guard on his way to work at a hotel in Copacabana, died instantly after he was hit in the head. Two other passengers were injured.

The escalation of violence in Rio de Janeiro's slums has also drastically affected the 'favela tourism' industry which once boomed in the city.

After the two-mile-long cable car was inaugurated in the huge Complexo do Alemao favela, enabling residents to get from one end of the hilly slum to the other in just 16 minutes, the unlikely tourist attraction was receiving more than 12,000 visitors every day - more than Rio's famous statue of Christ and Sugarloaf Mountain combined.

The popularity of the favela, which is also built along the Yellow Line and home to 100,000 people, was helped by a high-profile visit by Prince Harry, as well as actors Anna Hathaway and Jesse Eisenberg, after it was 'pacified' following occupation by Brazil's military in 2010.

But after confrontations between the slum's Police Pacification Unit and traffickers started to become more frequent, the number of tourists riding the cable car has plummeted to just a handful today.

The violence even led to ice-cream makers Kibon, owned by Anglo-Dutch company Unilever, cancelling their sponsorship of the cable car and removing their logo and adverts from the stations and pods.

Local tourist guide Cleber Araujo, 40, said his income, as well as the amount made from tourism by local shops and businesses, has dropped by 80 per cent in the last two years.

He said: 'There are shootouts every day. Even the embassies are now warning tourists not to come here. And I don't blame them.

The Olympic Stadium in Rio de Janeiro, which is set to host the Games, which begin in just seven weeks time

The Red Line road will be used by athletes and foreign dignitaries to take them from Rio's airport to the Olympic village, pictured

The athlete's village was officially opened yesterday and will house thousands of participants taking part in the Games

'Imagine being in a tiny cable car suspended high in the air when the bullets start flying down below.

'When the shooting starts the cable cars stop until it is safe to move again. If you're stuck in one it's terrifying.

'Don't come to Rio de Janeiro. Right now, Rio is a dangerous place to be. Here, there won't be any Olympics, there won't be any celebrations. There will just be more shootings.'

While Adenise Moraes da Silva, 51, whose son Caio, 20, was killed by a stray bullet fired by policemen in the Alemao favela in May last year, also had a warning for visitors to the Games.

Adenise claims that, in the last two months, she has lost five friends to the violence - two killed by drug dealers, two by police, and one victim of a stray bullet.

And she, too, tells Olympic visitors: 'If I were choosing whether to come to Rio, I wouldn't come at this moment. It's too dangerous.

'The state of Rio de Janeiro is bankrupt, there's no money, no jobs, people are becoming desperate and many are turning back to crime.