All six Gulf states had confirmed cases of the omicron variant in their territories, but official daily coronavirus data does not provide a breakdown by COVID-19 variant.
Saudi Arabia, the largest with a population of some 30 million, on Tuesday registered 2,585 new infections, up from some 1,000 cases announced on Sunday. It is still below a peak of more than 4,700 in June 2020.
Saudi authorities on Dec 30 made wearing masks in public compulsory again, after having earlier that month advised against non-essential travel overseas.
Much smaller neighbour Qatar reported 1,695 new coronavirus cases on Tuesday, the highest daily number since last summer. For days, crowds have queued at PCR testing sites in Qatar, which in January reintroduced remote school learning.
Soha al-Bayat, Qatar's head of vaccination, told state television on Sunday that a spike in the last two weeks was "related to the omicron variant" and that more recent cases were among unvaccinated individuals, including children, and people who received two doses more than six months ago.
Regional tourism and commercial hub the United Arab Emirates saw daily cases cross the 2,500-level on Sunday, as it hosts a world fair during its peak tourist season.
Kuwait registered 1,492 new daily cases on Tuesday, levels last seen in July 2021. Authorities earlier this week banned public events in closed spaces until Feb. 28.
Bahrain, where the daily number of cases peaked at some 3,000 last May before falling to around 100 in July, on Tuesday registered close to 900 infections. The island state in December limited non-essential activities to fully vaccinated individuals.