TAIPEI, Jan 22 (Reuters) - Taiwan"s government ordered a tightening of controls on Saturday after a rare spike in domestic transmission of the Omicron variant of COVID-19, saying it needed to act now to prevent being overwhelmed even though overall numbers remain quite low. After months of no or few community infections, Taiwan has seen a small rise in local COVID-19 cases since the start of the month, almost all Omicron, mainly linked to workers at the main international airport in the northern city of Taoyuan who were infected by arriving passengers. The infections have gradually spread although numbers remain comparatively low with a dozen or so new cases a day, but on Friday evening the government announced 60 new cases at a factory near the airport after testing 1,000 workers. There have been no deaths and most of the cases have had only mild or no symptoms. Speaking to reporters, officials announced a series of new steps, including a ban on eating and drinking on public transport and limits on the number of people visiting temples, ahead of the week-long Lunar New Year holiday which starts at the end of this month. Testing will be expanded to reach the largest number of possible contacts, said Health Minister Chen Shih-chung. "Of course we think this pandemic is threatening, so we must raise our vigilance," he said. In a statement, Premier Su Tseng-chang said even though this outbreak has brought no serious illness, steps needed to be taken now. "If the pandemic cannot be contained, it will still cause a burden on the medical system," he said. Taiwan has been highly successful at controlling the pandemic due to early and strict border checks and a well-oiled tracing system. Current new daily cases are well below the middle of last year when thousands were infected during a three-month domestic outbreak, and life has carried on as normal for most people. More than 70% of people in Taiwan have received two vaccine doses and booster shots are currently being rolled out, though only around 15% of residents have had their third shot so far.