An international research group says the heavy rain that caused extensive flooding in Libya earlier this month was up to 50 times more likely to occur today than in the late 19th century, before climate change.

The World Weather Attribution group released the results of a study on Tuesday on the torrential rainfalls across the Mediterranean region in early September.

Heavy rain brought by a developed low pressure system caused dams to collapse in eastern Libya on September 11. Some observers say the death toll could exceed 20,000.

The scientists compared the probability of heavy rains in the late 19th century with expectations today when temperatures are 1.2 degrees Celsius higher on average.

They said, "an event as extreme as the one observed over Libya has become up to 50 times more likely and up to 50 percent more intense" compared to the pre-climate change era.

The team noted that the ongoing conflict and state fragility in Libya compounded the effects of the flooding, increasing peoples' risk and the resulting impacts.