The current midnight to 4 am curfew will remain in place.
Omicron, first detected by South Africa and reported to the WHO on November 24.
Rwanda has detected its first six cases of the fast-spreading Covid-19 Omicron variant, prompting the government to escalate pandemic measures, including shutting down nightclubs and extending quarantines for international travellers.
Visitors will now be required to quarantine for three days instead of the current 24 hours, the government announced, after recording six cases of the Omicron variant in travellers and their contacts.
"A Covid-19 PCR test will be taken upon arrival and an additional test, taken on day three and on day seven at own cost, from the arrival date," the Ministry of Health said in a statement late Tuesday.
The current midnight to 4 am curfew will remain in place while nightclubs have been ordered to close their doors barely three months after reopening.
Omicron, first detected by South Africa and reported to the WHO on November 24, has a large number of mutations, leading many governments to swiftly reimpose containment measures to rein in transmission.
Early data suggests it is more transmissible than the Delta variant, which was first identified in India and accounts for the bulk of the world's coronavirus cases.
Rwanda, a country of 13 million people, has enforced some of the strictest containment measures on the continent and implemented a rigorous regime of testing and contact-tracing.
Last month, it became the first country in East Africa to bar direct flights to and from nine countries in southern Africa where the Omicron variant was first reported.
In total, the country has registered 100,763 cases of Covid-19 and 1,344 deaths, according to official figures.
Rwanda has so far fully vaccinated 4.2 million people -- around 60 percent of Rwandans aged 18 and above.
Unlike other countries in the region, it has also started administering vaccine booster shots to eligible adults.