The incident happened when the driver tried to avoid a Saudi-registered car, which allegedly changed lanes at high speed in the Seef District at around 6.15am, traffic sources told the GDN.
They said the driver was thought to be drunk and fled the scene.
Paramedics took five of the injured men to Salmaniya Medical Complex (SMC).
Three of them, who suffered from abrasions and concussions, were discharged after receiving treatment.
But one, identified as Anwar Noor Mian, 35, from Bangladesh, suffered serious head injuries and underwent emergency live-saving brain surgery yesterday.
Sources said there were 12 people riding in the open-top truck, which was heading towards a worksite in the Seef District.
Traffic officials declined to name the company they were working for, but doctors said the labourers who were discharged were illegal free visa workers.
"However, there is soon going to be a complete ban on all such open trucks carrying labourers,"
It's a good thing those workers are actually provided with such health care. I can't imagine how furious their employer is to be paying for all their medical expenses. Why do I think he's that cheap? Well, for starters, he couldn't provide them with the cheapest of vans to transport them and instead chose to carry them around in a lorry the same way one would carry around heavy duty tools.
I've been hearing so much talk about banning trucks carrying workers to and from work each day, but nothing has been done. There will always be some cheapskate trying to find ways to spend less on already underpaid workers. When I go to Bahrain, people would think the first thing I notice are the new shiny glass buildings being erected all around the city , but what catches my eyes first and foremost are the laborers and the open top trucks waiting to drive them back to their employer's sorry excuse for a home.
I remember Qatar talking about a similar plan a couple of years ago but don't know if they did anything about it. These trucks, in which the workers often stay standing or taking turns sitting, are an obvious risk and it's about time governments did something about it.