While alien hunters concentrate their energies on pictures from Mars or the top secret Area 51 base in Nevada, an island in central America was the location of a spate of UFO sightings that was officially investigated by Brazilian officials.

‘Operation Saucer’ was an investigation into a terrifying series of reported incidents in 1977 where residents in the Brazilian city of Colares claimed that they not only witnessed flying saucers – but they were also being attacked by them.

Bright objects of differing shapes, sizes and colours were said to have been flying at low altitudes – just a few metres above the tops of trees – and firing light beams at people on the ground below.

Several witnesses claimed to have seen beings piloting the crafts, describing them as no more than three to four feet tall.

What separates these sightings from the usual glimpses of UFOs in the skies are the numerous and recurring injuries that people suffered.

Sightings: Photographs were taken by officials of bright lights in the sky (Operation Saucer)

The beams gave off intense beams of radiation that caused puncture marks and lesions, with some reporting to local media at the time that it felt like a “heavy weight pushed against their chest”.

A report into the claims made by the victims stated: “The beam was about seven or eight centimetres in diameter and white in colour.

“It never hunted for them but hit them suddenly. When they tried to scream no sound would come out, but their eyes remained open.

“The beam felt hot, almost as hot as a cigarette burn.”

Describing the injuries, Doctor Wellaide Cecim Carvalho – who worked in a health care unit in the area during the 1970s – wrote: “All of them had suffered lesions to the face or the thoracic area.

Incidents: Numerous residents in Colares said they were attacked by flying saucers (Google)

“The lesions, looking like radiation injuries, began with intense reddening of the skin in the affected area.