Groups of Omanis have gathered to protest against unemployment in at least two cities, authorities and activists say, in the first show of dissent since the new sultan acceded the throne.
Videos and photos posted on social media showed protesters gathering in Salalah, in the south, and Sohar in the north.
A heavy presence of security forces, with convoys of military and police vehicles, could be seen on the videos, including where police forces fired tear gas and arrested demonstrators.
The protests are the first to take place under Sultan Haitham, who took power in January 2020 after the death of long-ruling Sultan Qaboos.
The coronavirus crisis and low oil prices have battered state coffers.
Oman has long had plans to reform its economy, diversify revenues and introduces sensitive tax and subsidies reform but these dragged under the late Sultan Qaboos.
His successor, Sultan Haitham, has introduced a series of reforms to try and make government finances sustainable.
Oman had demonstrations in early 2011 following the outbreak of revolts in the region.
But unlike in Tunisia, Egypt and Bahrain, protests in the sultanate focused on jobs and alleged corruption rather than political change.
Oman's government did not immediately respond to a request for comment.
State media reported on the protests on Monday, saying university graduates were calling on the government to provide jobs.
The labour issue is "one of the most important priorities" for the country's ruler, state-run Oman News said.
In Sohar, protesters could be seen outside a regional office of the Labour Ministry and in the surrounding areas, holding up signs calling for civil rights and chanting.
Some videos showed people throwing stones at police cars while security forces fired tear gas canisters at the protesters.
"Your majesty Sultan Haitham, who the unemployed and fired citizens would look at, after God, if it's not you ?" read one of the signs.
Small protests also took place in Sohar on Sunday, which also drew a large police response.
In a tweet, the country's labour ministry acknowledged Sunday's protests and said the protesters' demands of employment and complaints of lay-offs "were heard".
Oman's former minister of state for foreign affairs Yousuf bin Alawi bin Abdullah said in an interview with Oman state TV last month that the region was close to another Arab Spring.