Several parts of Oman suffered power cuts on Monday following "a technical failure" in part of the country's electrical grid.
Electricity and internet supply went down from about 2pm in places such as the capital Muscat.
The Oman News Agency said an unspecified number of areas were "facing some interruptions, and they are being dealt with by the Oman Electricity Transmission Company".
"The electricity is currently being restored gradually," it added.
The Authority for Public Services Regulation confirmed a "partial blackout".
It said Muscat and the areas surrounding the capital ― south Al Batinah, north and south Al Sharqiyah and Al Dakhiliyah — were all affected.
Power should be restored "within the next four hours", the authority said shortly before 3pm.
Oman's utility operator, Nama, said the cuts were caused by a "technical failure in one of the transmission lines of the network" and that work was under way to restore services.
At Muscat International Airport, officials said it was "expected that operations will be affected by this out of [our] control malfunction".
'High heat a factor'
An engineer who works for a government ministry told The National that the heat — which was in the high 40s on Monday — was thought to have been a factor.
"Power transformers failed from the intense summer heat and caused severe burning of electric cables that supplied houses and businesses," he said.
Yahya Al Kindi, a retired weather forecaster at the Meteorological Office, said such hot days "are rare for September".
Traffic lights were out in some areas, according to videos posted online. In one, a local man helped to ensure traffic moved at a busy junction.
Some colleges sent students home for the day.
“We were told to go home and classes were cancelled,” Salma Al Habsi, a business student at the National University of Science and Technology, said.
Internet supply was patchy, residents said.
“I am using my mobile phone internet provided by Omantel but my home internet is off because of the power outage. No TV or radio,” said Mohammed Al Saifi, a resident of Muscat.
Rashid Al Salami, a supermarket owner in Seeb, an area in Muscat, told The National that he was trying to prevent frozen produce from being spoilt.
“The emergency electricity staff cannot be reached since the calls are not going through,” he said.
The main state-owned oil company, Petroleum Development Oman, said that claims on social media that the power cuts were caused by a fire at a power station were false.
"PDO is aware of a photo and a message claiming that a fire has broken out at Mina Al Fahal circulating on social media and WhatsApp. Please be advised that neither is true," it said.