Extreme rainfall in Afghanistan and devastating flash floods have killed at least 66 people and damaged homes, infrastructure, and farmlands across most of the country's provinces, authorities said on Tuesday.

The storms, which started over the weekend, are adding to the challenges facing Afghanistan, which is still recovering from decades of conflict and natural disasters, including unprecedented droughts in the past four years, as well as a series of deadly earthquakes.

"According to primary reports from the provinces, at least 66 people lost their lives, and 36 others are injured," Janan Sayeq, spokesperson of the National Disaster Management Authority, told Arab News on Tuesday.

The number of reported casualties has doubled since Sunday, raising fears the actual toll could be higher. Many of the victims were killed when their homes collapsed on them.

Heavy rainfall has caused widespread flash flooding in parts of Oman where authorities report at least 12 people have died.

According to figures from Oman's National Committee for Emergency Management, 90 mm of rain fell in Al Mudhaibi in the North Al Sharqiyah Governorate in a period from 14 to early 15 April. Figures from the World Meteorological Organization (WMO) show 64 mm of rain fell at Marmul Airport in 24 hours to 15 April, while 59.2 mm fell in Qalhat, South Ash Sharqiyah Governorate.

Teams from Royal Oman Police (ROP) and Oman's Civil Defence and Ambulance Department Authority (CDAA) were called on to carry out multiple high water rescues. Many of those rescued were in vehicles trapped or swept away by fast-flowing wadi waters.

The Royal Oman Police rescued around 35 people stranded in the Wilayat of Ibra. Around 21 people were rescued after a school bus was trapped in flood waters in the Wilayat of Nizwa.

CDAA teams rescued 1,200 people from a school surrounded by flood waters in the Wilayat of Al Mudhaibi, North Al Sharqiyah Governorate. CDAA said all those rescued are in good health.

According to CDAA, at least 12 people have lost their lives in floods in Samad al Shan. A further five people were reported missing after being swept away by floods across areas of the Wilayat of Al Mudhaibi. As of 15 April the body of one of the missing, believed to be a young child, was found.

Torrential rains and high winds lashed parts of the Gulf on Tuesday as the death toll from storms in Oman rose to 18, many of them children.

Flights were canceled in Dubai, the region's financial hub, while schools were shut in the United Arab Emirates and Bahrain.

Flooding hit many areas of Dubai and Abu Dhabi, the UAE capital, and cut off major roads, snarling traffic and leaving cars stranded.

Dubai's skies, usually electric blue and cloudless, darkened to night-like conditions in mid-afternoon as a second storm front blew in.

The storms were expected to continue on Wednesday, the UAE's National Center of Meteorology said.

Some inland areas of the desert country recorded more than 80 millimeters (3.2 inches) of rain, approaching the annual average of about 100 mm.