The accident took place on a road between the northern cities of Fahud and Ibri.
Royal Oman Police (ROP) has confirmed the accident. The injured people have been admitted to hospitals.
Among the injured, 11 were from Oman, two were Saudis, one was Pakistani, one was Chinese and one remained unidentified, police said revising up the number initially injured.
Oman police spokesman Mohammed bin Salama al-Hashami said officials were still not sure what caused the collision. The dead included Saudis, Omanis and Asians, he said.
According to sources, the bus had left Salalah for Dubai at 3:30 p.m. on Monday with 28 passengers onboard.