The Dhofar governorate as well as Masirah are to remain closed until further notice, the Supreme Committee dealing with Covid-19 has announced on Tuesday.
Those Omani nationals who have requested to travel abroad during this time have been granted permission, Times of Oman reported.
However, they must agree to return once their reason for travelling overseas are met.
The Supreme Committee has also expressed its concern at the rising number of cases among citizens and residents, and has urged all to exercise caution during the pandemic.
Towards the end of May, Oman lifted the lockdown on Muscat, initially applied on April 10.
Read: Oman to lift lockdown in Muscat
Oman has reported a total of 1,389 cases of the novel coronavirus on July 14, of which 1,050 were Omanis.
The Ministry of Health has also confirmed 14 additional deaths, scaling the fatality toll to 273.
Currently, 149 people are admitted in the intensive care unit.
As many as 59,568 people have contracted the virus since its outbreak late last year, of whom 37,987 people have now recovered.