Two Emiratis drowned and another seven were rescued as flash floods caused by tropical storms swept across Oman on Thursday.
The two were among six men who died at the popular camping spot Wadi Andam in the southern Al Batnah region.
The others were two Omanis and two Pakistanis, the Royal Oman Police said. The victims' names have not been released.
Seven Emiratis had to be flown out by the air force on the same day, as their campsite at Wadi Tanaam, in Dhahirah, was flooded.
The storms, expected to continue for at least three days, prompted Oman's Meteorological Office to issue warnings yesterday against camping in low areas.
The office also said fishing boats should stay in port and swimmers should keep away from beaches.
Emergency services in Oman regularly warn campers to avoid low-lying areas close to mountains.
The sultanate's wadis, mountain ranges and coastal plains are also subjected to tropical storms that whip up winds and waters.
In November last year at least 14 people died and more than 200 were injured when a tropical storm battered much of the country.
Muscat bore the brunt of it, with houses and businesses damaged, vehicles swept away and police helicopters forced to evacuate patients from the city's Al Nahda and Khoula hospitals.
In the Batnah region in the north of the country, cyclonic winds ruined crops and destroyed farmhouses.
In June 2010, Cyclone Phet tore across eastern Oman, killing 17 people and injuring at least 52. In 2007, Cyclone Gonu, the strongest tropical cyclone on record in the Gulf, battered the country, killing at least 28 people and leaving another 8,000 homeless.