Public New Year celebrations and crowded events have been banned in Bangkok and many provinces.
The Centre for Covid-19 Situation Administration (CCSA) on Thursday announced a colour-coding system to identify which areas were most vulnerable to Covid-19 outbreaks.
Bangkok has been declared an "orange zone" -- and has strict measures. However, it has escaped a total lockdown.
CCSA spokesman Dr Taweesilp Visanuyothin announced four zones for Covid-19 control measures.
Red, orange, yellow and green are used for the different zones.
The red zone means maximum control and a high number of Covid-19 cases. The only province given this highest at-risk category is Samut Sakhon, the epicentre of the latest outbreak.
In this zone, crowd activities are banned and maximum Covid-19 prevention is imposed at workplaces, factories and workers' dormitories.
At-risk premises must close or limit their operating hours.
Measures in the three other zones are more relaxed.
The second-highest control zone (orange) covers provinces surrounding Samut Sakhon -- Bangkok, Samut Songkhram, Ratchaburi and Nakhon Pathom.
The high surveillance zone (yellow) comprises 25 provinces, while the surveillance zone (green) applies to provinces without infection cases.
Dr Taweesilp said New Year celebrations are banned in the red zone, unless entirely online. Public celebrations are banned in control or orange zones, including Bangkok. Parties can be held here, provided the number of attendees is limited.
In response to the CCSA order, two major New Year countdown celebrations in the capital have changed their plans. CentralWorld and Iconsiam on Thursday cancelled their countdown concerts. However, both will still go ahead with their firework displays, focusing on a live broadcast as a countdown event on Dec 31.
