Oman condemned American and British strikes on targets in rebel-held Yemen on Friday, warning of the risk of escalating conflict in the region.
Oman, a mediator in attempts to end Yemen's long-running civil war, expressed its "worry" at the strikes on Huthi rebel military targets that, according to the Huthis, left five people dead.
The Gulf sultanate "can only condemn the use of military action by friendly countries" while Israel pursues war against Hamas in the Gaza Strip, said a foreign ministry spokesman, according to official media.
"Oman has warned several times about the risk of the extension of the conflict in the region due to the ongoing Israeli aggression against the Palestinian territories," it said.
Kuwait's Foreign Ministry also expressed "great concern" about the strikes, echoing the view of Yemen's powerful neighbour Saudi Arabia, which is trying to extricate itself from a nine-year war with the Huthis.
The kingdom voiced its own concern after the UK and US military action, calling for "self-restraint and avoiding escalation".
In Bahrain, another of Yemen's Arab Gulf neighbours, protesters marched holding Palestinian flags and pro-Yemen banners after Friday prayers, denouncing the strikes.